Jet printing ink and method of ink jet printing

ABSTRACT

An ink for ink jet recording can be provided, in which an water-soluble dye having an oxidation potential more positive than 1.0 V (vs SCE) is dissolved or dispersed in an aqueous medium, which comprises at least one selected from compounds represented by the following general formula (A) and compounds represented by the following general formula (B), and which is excellent in discharge stability of the ink even after aging for a long period of time, good in color hue, and excellent in weathering resistance, light resistance, heat stability, and oxidation resistance: 
 
General formula (A)  
                 
 
in the formula, X represents a group containing carbonyl or a heteroatom, and Z 1  represents a group of atoms that can constitute a cyclic organic substance: 
General formula (B) 
 
X 1 —Y-Z 
 
in the formula, X 1  represents a group shown by —N(Q 1 )-Q 2 , Z represents a group shown by —N(Q 1 )-Q 2  or the like, Y represents a group shown by —W-(G) k -(H) n —, herein W and H represent a group shown by —CO—, G represents a divalent connecting group, Q 1 , Q 2 , and the like represent a hydrogen atom, an amino group, or the like, and k and n represent 0 or 1.

TECHNICAL FIELD

The present invention relates to an ink for ink jet recording and amethod of recording where the ink is used, and particularly to an inkfor ink jet recording that is high in quality of recorded images,excellent in discharge stability of an ink liquid even after aging for along period of time, and furthermore, excellent in keeping quality ofthe resulting images and a method of ink jet recording where the ink isused.

BACKGROUND ART

In recent years, with the spread of a computer an ink jet printer hasbeen widely used not only in offices but also in houses in order tocarry out printing or drawing on paper, film, cloth, and the like.

The method of ink jet recording include a system of discharging dropletsby applying a pressure by use of a piezoresistor, a system ofdischarging droplets by foaming ink with the aid of heat, a system ofusing ultrasonic waves, or a system of sucking and discharging dropletsby use of electrostatic force. As the ink for ink jet recording, anaqueous ink, an oily ink, or a solid (fusing type) ink is used.

Of these inks, the aqueous ink is comparatively superior to the oily inkand solid (fusing type) ink in view of possibility that manufacture,handling property, odor, safety, and the like can be simultaneouslysatisfied, and accordingly has become the leading ink for ink jetrecording at present.

Dyestuffs used for these inks for ink jet recording need high solubilityin solvent (ink medium), capability of high density recording, goodcolor hue, excellent resistance to light, heat, air, water, orchemicals, good fixing onto image-receiving materials and resistant toblurring, excellent keeping quality of ink, no toxicity, high purity,and furthermore availability at a reasonable price.

However, it is extremely difficult to search dyestuffs meeting theabove-described requirements at high levels. Particularly, excellentcolor hue and fastness are incompatible with each other in many cases,color materials for magenta or cyan ink that meet all requirements asdescribed above are difficult to acquire, and particularly it isdifficult to search for dyestuffs where good magenta or cyan color hueis compatible with light resistance enduring an oxidative atmosphere.

Accordingly, although various dyes and pigments have been proposed forthe ink jet already and used indeed, dyestuffs that meet allrequirements as described above have not been found out yet in thepresent state.

Hitherto well known dyes and pigments on which the color index numbersare bestowed are difficult to allow the compatibility of the color huewith the fastness required by the ink for ink jet recording.

Azo dyes derived from aromatic amines and five-membered heterocyclicamines as described in the following patent literature 1 are proposed asdyes improved in fastness. However, since these dyes have unpreferablecolor hues in yellow and cyan regions, the dyes have a problem ofdeteriorating the reproducibility of color.

The following patent literatures 2 and 3 disclose inks for ink jetrecording aiming at the compatibility between the color hue and lightresistance. However, the dyestuffs used in the respective literatureshave poor solubility in water in a case where they are used forwater-soluble inks. Use of the dyestuffs described in the respectiveliteratures for water-soluble inks for ink jet also introduces a problemin wet heat resistance.

Compounds and ink compositions described in the following patentliterature 4 are proposed as a means of solving these problems. Inaddition, in order to improve the color hue and light resistance, inksfor ink jet recording where a pyrazolyl aniline azo dyestuff is used aredescribed (the following patent literature 5). However, these inks forink jet recording were insufficient in both reproducibility of color andfastness of output images.

When glossy paper used exclusively for ink jet for photographic imagewas used for recording and stuck in a room, it was further found thatthe keeping quality of image was remarkably poor in some cases. Thepresent inventor presumes that this phenomenon is due to an oxidativegas in the air such as ozone. Furthermore, although this phenomenonoccurs with difficulty by putting the paper into a glass-made pictureframe and intercepting a stream of the air, this treatment results inlimiting conditions for use.

This phenomenon is particularly noticeable in the glossy paper usedexclusively for ink jet for photographic image and presents a seriousproblem to the present ink jet recording system where the photographicimage is one of important characteristics.

Furthermore, it was found that the aqueous ink had a problem ofdeteriorating readily the discharging properties thereof.

[List of Patent Literatures of Conventional Art]

-   -   [Patent Literature 1]    -   JP-A-55-161856    -   [Patent Literature 2]    -   JP-A-61-36362    -   [Patent literature 3]    -   JP-A-2-212566    -   [Patent Literature 4]    -   JP-T-11-504958 (the term “JP-T” as used herein means a published        Japanese translation of a PCT application)    -   [Patent Literature 5]    -   JP Application No. 2000-80733

The object of this invention is to provide an ink for ink jet recordingthat is excellent in discharge stability even after aging the ink over along period of time, in addition, good in color hue, and excellent inweathering resistance, light resistance, heat stability, and oxidationresistance and a recording method where the ink is used.

DISCLOSURE OF THE INVENTION

The object of this invention is achieved by means as described in thefollowing items 1 to 18.

1. An ink for ink jet recording comprising a dye dissolved or dispersesin an aqueous medium, wherein the dye is a water-soluble dye having anoxidation potential more positive than 1.0 V (vs SCE) and the inkcomprises at least one selected from compounds represented by thefollowing general formula (A) and compounds represented by the followinggeneral formula (B):General Formula (A)

in the formula, X represents a group containing carbonyl or aheteroatom; Z₁ represents a group of atoms that can form a cyclicorganic substance:General Formula (B)X¹—Y-Zin the formula, X¹ represents a group shown by —N(Q₁)-Q₂; Z represents agroup shown by —N(Q₁)-Q₂ or a group shown by —O-Q₃; Y represents a groupshown by —W-(G)_(k)-(H)_(n)—; W and H represent groups shown by —CO—,—SO₂—, or —PO(Q₄)—; G represents a divalent connecting group; Q₁ to Q₄represent any of a hydrogen atom, an amino group, an alkyl group, analkenyl group, an alkynyl group, an aryl group, a heterocyclic group, aheteroaryl group, an alkoxy group, an aryloxy group, a heterocyclic oxygroup, a heteroaryloxy group, an alkylamino group, an arylamino group, aheterocyclic amino group, and a heteroarylamino group; X and Z maycombine with each other to form a ring; K and n each represent 0 or 1.

2. The ink for ink jet recording as described in the item 1, wherein thedye is a magenta dye selected from an azo dye, and the magenta dye hasan absorption maximum in a spectral region of 500 to 580 nm in theaqueous medium.

3. The ink for ink jet recording as described in the item 2, wherein theazo dye has a chromophore represented by general formula: (heterocycleA)-N═N-(heterocycle B), in which the heterocycle A and the heterocycle Bin the above general formula may have the same structure.

4. The ink for ink jet recording as described in the item 2 or 3,wherein the azo dye is an azo dye having an aromatic nitrogen-containingsix-membered heterocycle linked directly to at least one side of the azogroup as a coupling component.

5. The ink for ink jet recording as described in claim 3 or 4, whereinthe azo dye is an azo dye having an aromatic amino group- or aheterocyclic amino group-containing structure as an auxochrome.

6. The ink for ink jet recording as described in any of the items 2 to5, wherein the azo dye is an azo dye having a steric structure.

7. The ink for ink jet recording as described in any of the items 2 to6, wherein the azo dye is a dye represented by the following generalformula (1):

-   -   In general formula (1), A represents a five-membered        heterocyclic group;    -   B¹ and B² each represents ═CR¹— or —CR²═, or either thereof        represents a nitrogen atom and the other represents ═CR¹— or        —CR²═; R⁵ and R⁶ each independently represent a hydrogen atom or        a substituent group, the substituent group represents an        aliphatic group, an aromatic group, a heterocyclic group, an        acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a        carbamoyl group, an alkylsulfonyl group, an arylsulfonyl group,        or a sulfamoyl group, and a hydrogen atom(s) on the respective        substituent groups may be substituted;    -   G, R¹, and R² each independently represent a hydrogen atom or a        substituent group, the substituent group represents a halogen        atom, an aliphatic group, an aromatic group, a heterocyclic        group, a cyano group, a carboxyl group, a carbamoyl group, an        alkoxycarbonyl group, an aryloxycarbonyl group, a heterocyclic        oxycarbonyl group, an acyl group, a hydroxy group, an alkoxy        group, an aryloxy group, a heterocyclic oxy group, a silyloxy        group, an acyloxy group, a carbamoyloxy group, an        alkoxycarbonyloxy group, an aryloxycarbonyloxy group, an amino        group, an acylamino group, an ureido group, a sulfamoylamino        group, an alkoxycarbonylamino group, an aryloxycarbonylamino        group, an alkylsulfonylamino group, an arylsulfonylamino group,        a heterocyclic sulfonylamino group, a nitro group, an alkylthio        group, an arylthio group, a heterocyclic thio group, an        alkylsulfonyl group, an arylsulfonyl group, a heterocyclic        sulfonyl group, an alkylsulfinyl group, an arylsulfinyl group, a        heterocyclic sulfinyl group, a sulfamoyl group, or a sulfo        group, and a hydrogen atom(s) on the respective substituent        groups may be substituted;    -   R¹ and R⁵, or R⁵ and R⁶ may be combined to form a five- or        six-membered ring.

8. The ink for ink jet recording as described in any of the items 2 to7, wherein a rate constant of ozone fading of a recorded image is5.0×10⁻² [hour⁻¹] or less.

9. The ink for ink jet recording as described in the item 1, wherein thedye is a phthalocyanine dye.

10. The ink for ink jet recording as described in the item 9, wherein aresidual ratio of dye (density after fading/initial density×100) is 60percent or more when kept in an ozone atmosphere of 5 ppm for 24 hr, ina monochromatic site printed so that the cyan reflection density in astatus A filter is from 0.9 to 1.1 by use of a monochrome of the ink(cyan).

11. The ink for ink jet recording as described in the items 9 or 10,wherein an amount of Cu ion running off into water is 20 percent or lessof the total dye after the ink undergoes ozone fading under thecondition of the item 10.

12. The ink for ink jet recording as described in any of the items 9 to11, wherein the phthalocyanine dye is a water-soluble dye having anelectron-withdrawing group at a β position of a benzene ring of thephthalocyanine.

13. The ink for ink jet recording as described in any of the items 9 to12, wherein the phthalocyanine dye is a water-soluble phthalocyanine dyeprepared by a process that does not go through a sulfonation ofnon-substituted phthalocyanine.

14. The ink for ink jet recording as described in any of the items 9 to13, wherein the phthalocyanine dye is represented by the followinggeneral formula (I):

in the above formula (I),

-   -   X₁, X₂, X₃, and X₄ each independently represent —SO-Z, —SO₂-Z,        —SO₂NR1R2, a sulfo group, —CONR1R2, or —CO₂R1;    -   the above Z represents a substituted or unsubstituted alkyl        group, a substituted or unsubstituted cycloalkyl group, a        substituted or unsubstituted alkenyl group, a substituted or        unsubstituted aralkyl group, a substituted or unsubstituted aryl        group, or a substituted or unsubstituted heterocyclic group; the        above R1 and R2 each independently represent a hydrogen atom, a        substituted or unsubstituted alkyl group, a substituted or        unsubstituted cycloalkyl group, a substituted or unsubstituted        alkenyl group, a substituted or unsubstituted aralkyl group, a        substituted or unsubstituted aryl group, or a substituted or        unsubstituted heterocyclic group, and when a plurality of Z's        exist, the Z's may be the same or different;    -   Y₁, Y₂, Y₃, and Y₄ each independently represent a monovalent        substituent group;    -   when any of X₁ to X₄ and Y₁ to Y₄ exists in plurality, they may        be the same or different;    -   a₁ to a₄ and b₁ to b₄ represent the number of substituent groups        X₁ to X₄ and Y₁ to Y₄, respectively, and a₁ to a₄ each        independently represent an integer of 0 to 4, all of them do not        represent 0 at the same time, and b₁ to b₄ each independently        represent an integer of zero to four;    -   M is a hydrogen atom, a metallic atom, or an oxide, a hydroxide        or a halide thereof.

15. The ink for ink jet recording as described in the item 14, whereinthe dye represented by general formula (I) is a dye represented by thefollowing general formula (II):

-   -   in the above general formula (II),    -   X₁₁ to X₁₄, Y₁₁ to Y₁₄, and M have the same meanings as X₁ to        X₄, Y₁ to Y₄, and M in general formula (I), respectively;    -   a₁₁ to a₁₄ each independently represent an integer of 1 or 2.

16. The ink for ink jet recording as described in any of the items 1 to15, which comprises an organic solvent having a boiling point of 150° C.or higher.

17. A method of ink jet recording, which comprises using the ink for inkjet recording as described in the items 1 to 16.

18. A method of ink jet recording, which comprises discharging inkdroplets according to a recording signal onto an image-receivingmaterial that has an image-receiving layer containing particles of awhite inorganic pigment on a support to record an image on theimage-receiving material, wherein the ink droplets comprises the ink forink jet recording as described in the items 1 to 16.

The present invention is hereinafter illustrated in further detail.

The applicant of this patent has intensively studied the ink for ink jetrecording and as a result, the characteristics required by dyes are 1)to have a good color hue and cause no change in color hue(solvatochromism), 2) to be excellent in resistance (light, ozone,NO_(x), solvent, oil, and water), 3) to be safe (causing no Ames, nocarcinogenicity, no skin irritation, and easy decomposability), 4) to bea low cost, 5) to have a high ε, 6) to have high solubility, and 7) tohave a strong fixing property to media.

Subsequently, the characteristics required by properties of ink andconcentrated ink are 1) to be uniform in spite of temperature and agingtime, 2) to be soiled with difficulty, 3) to be good in penetration tomedia, 4) to be uniform in size of droplets discharged, 5) to select nopaper, 6) to be easy in preparation of solution, 7) to cause no wrongdischarge, foam with difficulty, and allow foam to disappear easily, and8) to discharge stably.

The characteristics required by image are 1) to be fine withoutblurring, discoloration, and beading, 2) to have flaw resistance, 3) tobe high and uniform in gloss, 4) to be good in keeping quality of imageand excellent in fading balance, 5) to be quick in drying, 6) to beprinted at a high speed, and 7) to have no dependence on image densityin fading ratio.

Specific embodiments of this invention are hereinafter illustrated indetail.

[Magenta Dye]

In order to possess the characteristics at which this invention aims,the recording of image is carried out, as magenta ink, by use of a dyehaving the characteristics described in the above-described items 1 to7. Accordingly, these characteristics are illustrated as to the magentadye.

The magenta ink used as ink for ink jet recording of this invention hasa magenta dye selected from an azo dye and dissolved or dispersed in anaqueous medium, and the dye has, as fundamental characteristics, anabsorption maximum in the spectral region of 500 to 580 nm in theaqueous medium and an oxidation potential of 1.0 V (vs SCE) or positive.

The first structural characteristic of preferred dyes selected from theazo dye is to have a chromophore represented by general formula(heterocycle A)-N═N-(heterocycle B). In this case, heterocycle A andheterocycle B may have the same structure. Heterocycle A and heterocycleB are specifically five-membered or six-membered heterocycles, which areheterocycles selected from pyrazole, imidazole, triazole, oxazole,thiazole, selenazole, pyridone, pyrazine, pyrimidine, and pyridine.Specific examples are described in JP Application No. 2000-15853, JPApplication No. 2001-15614, JP-A-2002-309116, JP Application No.2001-195014, and the like.

Furthermore, the second preferred structural characteristics of theabove-described azo dye are to be an azo dye that has an aromaticnitrogen-containing six-membered heterocycle linked directly to at leastone side of the azo group as a coupling component, and specific examplesare described in 2001-110457.

The third preferred structural characteristic is that the auxochrome hasa structure of an aromatic ring amino group or a heterocyclic ring aminogroup, specifically an anilino group or a heterylamino group.

The fourth preferred structural characteristic is to have a stericstructure. Specific examples are described in JP Application No.2002-12015.

Of the preferred structural characteristics of the azo dye as describedabove, the most preferred dyes to achieve the object of this inventionare dyes represented by the following general formula (1).

In general formula (1), A represents a five-membered heterocyclic group.

B¹ and B² represent ═CR¹— and —CR²═, respectively, or either thereofrepresents a nitrogen atom and the other represents ═CR¹— or —CR²═. R⁵and R⁶ each independently represent a hydrogen atom or a substituentgroup, the substituent group represents an aliphatic group, an aromaticgroup, a heterocyclic group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, a carbamoyl group, an alkylsulfonyl group, anarylsulfonyl group, or a sulfamoyl group, and hydrogen atoms on therespective substituent groups may be replaced.

G, R¹, and R² each independently represent a hydrogen atom or asubstituent group, the substituent group represents a halogen atom, analiphatic group, an aromatic group, a heterocyclic group, a cyano group,a carboxyl group, a carbamoyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, a heterocyclic oxycarbonyl group, an acyl group,a hydroxy group, an alkoxy group, an aryloxy group, a heterocyclic oxygroup, a silyloxy group, an acyloxy group, a carbamoyloxy group, analkoxycarbonyloxy group, an aryloxycarbonyloxy group, an amino group, anacylamino group, an ureido group, a sulfamoylamino group, analkoxycarbonylamino group, an aryloxycarbonylamino group, analkylsulfonylamino group, an arylsulfonylamino group, a heterocyclicsulfonylamino group, a nitro group, an alkylthio group, an arylthiogroup, a heterocyclic thio group, an alkylsulfonyl group, anarylsulfonyl group, a heterocyclic sulfonyl group, an alkylsulfinylgroup, an arysulfinyl group, a heterocyclic sulfinyl group, a sulfamoylgroup, or a sulfo group, and hydrogen atoms on the respectivesubstituent groups may be replaced.

R¹ and R⁵ or R⁵ and R⁶ may combine to form a five or six-membered ring.

The dyes of general formula (1) are illustrated in further detail.

In general formula (1), A represents a five-membered heterocyclic group,and examples of the heteroatoms of the heterocycle include N, O, and S.A is preferably a nitrogen-containing five-membered heterocycle and theheterocycle may be further condensed with an aliphatic ring, an aromaticring, or an other heterocycle. Examples of preferred heterocycle Ainclude a pyrazole ring, an imidazole ring, a thiazole ring, anisothiazole ring, a thiadiazole ring, a benzothiazole ring, abenzoxazole ring, and a benzisothiazole ring. The respectiveheterocyclic rings may have a further substituent group. Of these, thepyrazole ring, the imidazole ring, the isothiazole ring, the thiadiazolering, the benzothiazole ring represented by the following generalformulas (a) and (f) are preferred.

In the above-described general formulas (a) to (f), R⁷ to R²⁰ representthe same substituent groups as G, R¹, and R² in general formula (1).

Of general formulas (a) to (f), the pyrazole ring and the isothiazolering represented by general formulas (a) and (b) are preferred, and thepyrazole ring represented by general formula (a) is most preferred.

In general formula (1), B¹ and B² represent ═CR¹— and —CR²═,respectively, or either thereof represents a nitrogen atom and the otherrepresents ═CR¹— or —CR²═, but those representing ═CR¹— and —CR²═,respectively, are more preferred.

R⁵ and R⁶ each independently represent a hydrogen atom or a substituentgroup, the substituent group represents an aliphatic group, an aromaticgroup, a heterocyclic group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, a carbamoyl group, an alkylsulfonyl group, anarylsulfonyl group, or a sulfamoyl group, and hydrogen atoms on therespective substituent groups may be replaced.

R⁵ and R⁶ preferably include the hydrogen atom, the aliphatic group, thearomatic group, the heterocyclic group, the acyl group, or thealkylsulfonyl or arylsulfonyl group. R⁵ and R⁶ are further preferablythe hydrogen atom, the aromatic group, the heterocyclic group, the acylgroup, or the alkylsulfonyl or arylsulfonyl group. R⁵ and R³ are mostpreferably the hydrogen atom, the aryl group, or the heterocyclic group.Hydrogen atoms on the respective substituent groups may be replaced.However, R⁵ and R⁶ can not be hydrogen atoms at the same time.

G, R¹, and R² each independently represent a hydrogen atom or asubstituent group, the substituent group represents a halogen atom, analiphatic group, an aromatic group, a heterocyclic group, a cyano group,a carboxyl group, a carbamoyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, a heterocyclic oxycarbonyl group, an acyl group,a hydroxyl group, an alkoxy group, an aryloxy group, a heterocyclic oxygroup, a silyloxy group, an acyloxy group, a carbamoyloxy group, analkoxycarbonyloxy group, an aryloxycarbonyloxy group, an amino group, anacylamino group, an ureido group, a sulfamoylamino group, analkoxycarbonylamino group, an aryloxycarbonylamino group, analkylsulfonylamino group, an arylsulfonylamino group, a heterocyclicsulfonylamino group, a nitro group, an alkylthio group, an arylthiogroup, a heterocyclic thio group, an alkylsulfonyl group, anarylsulfonyl group, a heterocyclic sulfonyl group, an alkylsulfinylgroup, an arylsulfinyl group, a heterocyclic sulfinyl group, a sulfamoylgroup, or a sulfo group, and hydrogen atoms on the respectivesubstituent groups may be replaced.

G is preferably the hydrogen atom, the halogen atom, the aliphaticgroup, the aromatic group, the hydroxy group, the alkoxy group, thearyloxy group, the acyloxy group, the heterocyclic oxy group, the aminogroup, the acylamino group, the ureido group, the sulfamoylamino group,the alkoxycarbonylamino group, the aryloxycarbonylamino group, thealkylthio or arylthio group, or the heterocyclic thio group; furtherpreferably the hydrogen atom, the halogen atom, the alkyl group, thehydroxy group, the alkoxy group, the aryloxy group, the acyloxy group,the amino group, or the acylamino group; and of these, most preferablythe hydrogen atom, the amino group (preferably anilino group), and theacylamino group. Hydrogen atoms on the respective substituent groups maybe replaced.

R¹ and R² preferably include a hydrogen atom, an alkyl group, a halogenatom, an alkoxycarbonyl group, a carboxyl group, a carbamoyl group, ahydroxy group, an alkoxy group, and a cyano group. Hydrogen atoms on therespective substituent groups may be replaced.

R¹ and R⁵ or R⁵ and R⁶ may combine to form a five or six-membered ring.

When A has a substituent group or when substituent groups on R¹, R², R⁵,R⁶, or G have further substituent groups, the substituent groups caninclude those included in the above-described G, R¹, and R².

When the dyes of this invention are water-soluble dyes, it is preferablethat the dyes have an ionic hydrophilic group at any position on A, R¹,R², R⁵, R⁶, and G as a substituent group. The ionic hydrophilic groupused as the substituent group includes a sulfo group, a carboxyl group,a phosphono group, a quaternary ammonium group, and the like. As theabove-described ionic hydrophilic group, the carboxyl group, thephosphono group, and the sulfo group are preferred, and the carboxylgroup and the sulfo group are particularly preferred. The carboxylgroup, the phosphono group, and the sulfo group may be in the form ofsalts, and examples of counter ions to form the salts include anammonium ion, an alkali metal ion (e.g., lithium ion, sodium ion, andpotassium ion), and an organic cation (e.g., tetramethylammonium ion,tetramethylguanidinium ion, and tetramethylphosphonium).

Terms (substituent groups) used in the present description areillustrated. These terms are common even among different signs ingeneral formula (1) and general formula (1a) shown later.

The halogen atom includes a fluorine atom, a chlorine atom, and abromine atom.

The aliphatic group means an alkyl group, a substituted alkyl group, analkenyl group, a substituted alkenyl group, an alkynyl group, asubstituted alkynyl group, an aralkyl group, and a substituted aralkylgroup. In the present description, “substituted” used in “substitutedalkyl group” and the like shows that a hydrogen atom existing on an“alkyl group” is replaced by a substituent group included in theabove-described G, R¹, or R².

The aliphatic group may have a branch or may form a ring. The carbonnumber of the aliphatic group is preferably from one to 20, and furtherpreferably from one to 16. The aryl moieties of the aralkyl group andthe substituted aralkyl group are preferably a phenyl group or anaphthyl group and particularly preferably the phenyl group. Examples ofthe aliphatic groups include a methyl group, an ethyl group, a butylgroup, an isopropyl group, a t-butyl group, a hydroxyethyl group, amethoxyethyl group, a cyanoethyl group, a trifluoromethyl group, a3-sulfopropyl group, a 4-sulfobutyl group, a cyclohexyl group, a benzylgroup, a 2-phenetyl group, a vinyl group, and an allyl group.

The aromatic group means an aryl group and a substituted aryl group. Thearyl group is preferably a phenyl group or a naphthyl group andparticularly preferably the phenyl group. The carbon number of thearomatic group is preferably from six to 20 and further preferably fromsix to 16.

Examples of the aromatic groups include a phenyl group, a p-tolyl group,a p-methoxyphenyl group, an o-chlorophenyl group, and am-(3-sulfopropylamino)phenyl group.

The heterocyclic group includes a substituted heterocyclic group. Theheterocyclic group may be condensed with an aliphatic ring, an aromaticring, or another heterocycle. The above-described heterocyclic group ispreferably a five or six-membered heterocyclic group. Examples of theabove-described substituent groups include an aliphatic group, a halogenatom, an alkylsulfonyl group, an arylsulfonyl group, an acyl group, anacylamino group, a sulfamoyl group, a carbamoyl group, an ionichydrophilic group, and the like. Examples of the above-describedheterocyclic group include a 2-pyridyl group, a 2-thienyl group, a2-thiazolyl group, a 2-benzothiazolyl group, a 2-benzoxazolyl group, anda 2-furfuryl group.

The carbamoyl group includes a substituted carbamoyl group. An exampleof the above-described substituent group is an alkyl group. Examples ofthe above-described carbamoyl group include a methylcarbamoyl group anda dimethylcarbamoyl group.

The alkoxycarbonyl group includes a substituted alkoxycarbonyl group.Alkoxycarbonyl groups having a carbon number of two to 20 are preferredas the above-described alkoxycarbonyl groups. An example of theabove-described substituent group is an ionic hydrophilic group.Examples of the above-described alkoxycarbonyl groups include amethoxycarbonyl group and an ethoxycarbonyl group.

The aryloxycarbonyl group includes a substituted aryloxycarbonyl group.Aryloxycarbonyl groups having a carbon number of seven to 20 arepreferred as the above-described aryloxycarbonyl groups. An example ofthe above-described substituent group is an ionic hydrophilic group. Anexample of the above-described aryloxycarbonyl groups is aphenoxycarbonyl group.

The heterocyclic oxycarbonyl group includes a substituted heterocyclicoxycarbonyl group. The heterocycle includes heterocycles described aboveas the heterocyclic groups. Heterocyclic oxycarbonyl groups having acarbon number of two to 20 are preferred as the above-describedheterocyclic oxycarbonyl groups. An example of the above-describedsubstituent group is an ionic hydrophilic group. An example of theabove-described heterocyclic oxycarbonyl group is a 2-pyridyloxycarbonylgroup.

The acyl group includes a substituted acyl group. Acyl groups having acarbon number of one to 20 are preferred as the above-described acylgroups. An example of the above-described substituent group is an ionichydrophilic group. Examples of the above-described acyl groups includean acetyl group and a benzoyl group.

The alkoxy group includes a substituted alkoxy group. Alkoxy groupshaving a carbon number of one to 20 are preferred as the above-describedalkoxy groups. Examples of the above-described substituent group includean alkoxy group, a hydroxyl group, and an ionic hydrophilic group.Examples of the above-described alkoxy groups include a methoxy group,an ethoxy group, an isopropoxy group, a methoxyethoxy group, ahydroxyethoxy group, and a 3-carboxypropoxy group.

The aryloxy group includes a substituted aryloxy group. Aryloxy groupshaving a carbon number of six to 20 are preferred as the above-describedaryloxy groups. Examples of the above-described substituent groupinclude an alkoxy group and an ionic hydrophilic group. Examples of theabove-described aryloxy groups include a phenoxy group, ap-methoxyphenoxy group, and an o-methoxyphenoxy group.

The heterocyclic oxy group includes a substituted heterocyclic oxygroup. The heterocycle includes heterocycles described above as theheterocyclic groups. Heterocyclic oxy groups having a carbon number oftwo to 20 are preferred as the above-described heterocyclic oxy groups.Examples of the above-described substituent group include an alkylgroup, an alkoxy group, and an ionic hydrophilic group. Examples of theabove-described heterocyclic oxy groups include a 3-pyridyloxy group anda 3-thienyloxy group.

Silyloxy groups substituted by aliphatic groups having a carbon numberof one to 20 or aromatic groups are preferred as the silyloxy groups.Examples of the above-described silyloxy groups includetrimethylsilyloxy and diphenylmethylsilyloxy.

The acyloxy group includes a substituted acyloxy group. Acyloxy groupshaving a carbon number of one to 20 are preferred as the above-describedacyloxy groups. An example of the above-described substituent group isan ionic hydrophilic group. Examples of the above-described acyloxygroups include an acetoxy group and a benzoyloxy group.

The carbamoyloxy group includes a substituted carbamoyloxy group. Anexample of the above-described substituent group is an alkyl group. Anexample of the above-described carbamoyloxy group is anN-methylcarbamoyloxy group.

The alkoxycarbonyloxy group includes a substituted alkoxycarbonyloxygroup. Alkoxycarbonyloxy groups having a carbon number of two to 20 arepreferred as the above-described alkoxycarbonyloxy groups. Examples ofthe above-described alkoxycarbonyloxy groups include amethoxycarbonyloxy group and an isopropoxycarbonyloxy group.

The aryloxycarbonyloxy group includes a substituted aryloxycarbonyloxygroup. Aryloxycarbonyloxy groups having a carbon number of seven to 20are preferred as the above-described aryloxycarbonyloxy groups. Anexample of the above-described aryloxycarbonyloxy groups is aphenoxycarbonyloxy group.

The amino group includes a substituted amino group. The substituentgroup includes an alkyl group, an aryl group, and a heterocyclic group,and the alkyl group, the aryl group, and the heterocyclic group mayfurther have a substituent group. The alkylamino group includes asubstituted alkylamino group. Alkylamino groups having a carbon numberof one to 20 are preferred as the alkylamino groups. An example of theabove-described substituent group is an ionic hydrophilic group.Examples of the above-described alkylamino groups include a methylaminogroup and a diethylamino group.

The arylamino group includes a substituted arylamino group. Arylaminogroups having a carbon number of six to 20 are preferred as theabove-described arylamino group. Examples of the above-describedsubstituent group include a halogen atom and an ionic hydrophilic group.Examples of the above-described arylamino groups include a phenylaminogroup and a 2-chlorophenylamino group.

The heterocyclic amino group includes a substituted heterocyclic aminogroup. The heterocycle includes heterocycles described above as theheterocyclic groups. Heterocyclic amino groups having a carbon number oftwo to 20 are preferred as the above-described heterocyclic aminogroups. Examples of the substituent group include an alkyl group, ahalogen atom, and an ionic hydrophilic group.

The acylamino group includes a substituted acylamino group. Acylaminogroups having a carbon number of two to 20 are preferred as theabove-described acylamino groups. An example of the above-describedsubstituent group is an ionic hydrophilic group. Examples of theabove-described acylamino groups include an acetylamino group, apropionylamino group, a benzoylamino group, an N-phenylacetylaminogroup, and a 3,5-disulfobenzoylamino group.

The ureido group includes a substituted ureido group. Ureido groupshaving a carbon number of one to 20 are preferred as the above-describedureido groups. Examples of the above-described substituent group includean alkyl group and an aryl group. Examples of the above-described ureidogroups include a 3-methylureido group, a 3,3-dimethylureido group, and a3-phenylureido group.

The sulfamoylamino group includes a substituted sulfamoylamino group. Anexample of the above-described substituent group is an alkyl group. Anexample of the above-described sulfamoylamino group is anN,N-dipropylsulfamoylamino group.

The alkoxycarbonylamino group includes a substituted alkoxycarbonylaminogroup. Alkoxycarbonylamino groups having a carbon number of two to 20are preferred as the above-described alkoxycarbonylamino groups. Anexample of the above-described substituent group is an ionic hydrophilicgroup. An example of the above-described alkoxycarbonylamino group is anethoxycarbonylamino group.

The aryloxycarbonylamino group includes a substitutedaryloxycarbonylamino group. Aryloxycarbonylamino groups having a carbonnumber of seven to 20 are preferred as the above-describedaryloxycarbonylamino groups. An example of the above-describedsubstituent group is an ionic hydrophilic group. An example of theabove-described aryloxycarbonylamino group is a phenoxycarbonylaminogroup.

The alkylsulfonylamino group and the arylsulfonylamino group include asubstituted alkylsulfonylamino group and a substituted arylsulfonylaminogroup, respectively. Alkylsulfonylamino groups and arylsulfonylaminogroups having a carbon number of one to 20 are preferred as theabove-described alkylsulfonylamino groups and arylsulfonylamino groups,respectively. An example of the above-described substituent groups is anionic hydrophilic group. Examples of the above-describedalkylsulfonylamino groups and arylsulfonylamino groups include amethylsulfonylamino group, an N-phenyl-methylsulfonylamino group, aphenylsulfonylamino group, and a 3-carboxyphenylsulfonylamino group.

The heterocyclic sulfonylamino group includes a substituted heterocyclicsulfonylamino group. The heterocycle includes heterocycles describedabove as the heterocyclic groups. Heterocyclic sulfonylamino groupshaving a carbon number of one to 12 are preferred as the above-describedheterocyclic sulfonylamino groups. An example of the above-describedsubstituent group is an ionic hydrophilic group. Examples of theabove-described heterocyclic sulfonylamino groups include a2-thienylsulfonylamino group and a 3-pyridylsulfonylamino group.

The alkylthio group, the arylthio group, the heterocyclic thio groupinclude a substituted alkylthio group, a substituted arylthio group, anda substituted heterocyclic thio group, respectively. The heterocycleincludes heterocycles described above as the heterocyclic groups. Theabove-described alkylthio group, arylthio group, and heterocyclic thiogroup are preferably those having a carbon number of one to 20,respectively. An example of the above-described substituent groups is anionic hydrophilic group. Examples of the above-described alkylthiogroups, arylthio groups, and heterocyclic thio groups include amethylthio group, a phenylthio group, and a 2-pyridylthio group.

The alkylsulfonyl group and the arylsulfonyl group include a substitutedalkylsulfonyl group and a substituted arylsulfonyl group, respectively.Examples of the alkylsulfonyl group and the arylsulfonyl group include amethylsulfonyl group and a phenylsulfonyl group, respectively.

The heterocyclic sulfonyl group includes a substituted heterocyclicsulfonyl group. The heterocycle include heterocycles described above asthe heterocyclic groups. Heterocyclic sulfonyl groups having a carbonnumber of one to 20 are preferred as the above-described heterocyclicsulfonyl group. An example of the above-described substituent group isan ionic hydrophilic group. Examples of the above-described heterocyclicsulfonyl groups include a 2-thienylsulfonyl group and a3-pyridylsulfonyl group.

The alkylsulfinyl group and the arylsulfinyl group include a substitutedalkylsulfinyl group and a substituted arylsulfinyl group, respectively.Examples of the alkylsulfinyl group and the arylsulfinyl group include amethylsulfinyl group and a phenylsulfinyl group, respectively.

The heterocyclic sulfinyl group includes a substituted heterocyclicsulfinyl group. The heterocycle include heterocycles described above asthe heterocyclic groups. Heterocyclic sulfinyl groups having a carbonnumber of one to 20 are preferred as the above-described heterocyclicsulfinyl group. An example of the above-described substituent group isan ionic hydrophilic group. An example of the above-describedheterocyclic sulfinyl group is a 4-pyridylsulfinyl group.

The sulfamoyl group includes a substituted sulfamoyl group. An exampleof the above-described substituent group is an alkyl group. Examples ofthe above-described sulfamoyl group include a dimethylsulfamoyl groupand a di(2-hydroxyethyl)sulfamoyl group.

Of general formula (1), a particularly preferred structure is thatrepresented by the following general formula (1a).

In the formula, R¹, R², R⁵, and R⁶ have the same meanings as in generalformula (1).

R³ and R⁴ each independently represent a hydrogen atom or a substituentgroup and the substituent group represents an aliphatic group, anaromatic group, a heterocyclic group, an acyl group, an alkoxycarbonylgroup, an aryloxycarbonyl group, a carbamoyl group, an alkylsulfonylgroup, an arylsulfonyl group, or a sulfamoyl group. Of these, thehydrogen atom, the aromatic group, the heterocyclic group, the acylgroup, the alkylsulfonyl group and the arylsulfonyl group are preferredand the hydrogen atom, the aromatic group, and the heterocyclic groupare particularly preferred.

Z¹ represents an electron-withdrawing group having a Hammett'ssubstituent constant σ_(p) value of 0.20 or higher. Z¹ is preferably anelectron-withdrawing group having a σ_(p) value of 0.30 or higher,further preferably an electron-withdrawing group having a σ_(p) value of0.45 or higher, and particularly preferably an electron-withdrawinggroup having a σ_(p) value of 0.60 or higher, but it is desirable thatno σ_(p) value exceeds 1.0. Although specific preferred substituentgroups include electron-withdrawing substituent groups as shown later,particularly preferred substituent groups include acyl groups having acarbon number of two to 20, alkyloxycarbonyl groups having a carbonnumber of two to 20, a nitro group, a cyano group, alkylsulfonyl groupshaving a carbon number of one to 20, arylsulfonyl groups having a carbonnumber of six to 20, carbamoyl groups having a carbon number of one to20, and halogenated alkyl groups having a carbon number of one to 20.The cyano group, the alkylsulfonyl groups having a carbon number of oneto 20, and the arylsulfonyl groups having a carbon number of six to 20are particularly preferred and the cyano group is most preferred.

Z² represents a hydrogen atom or a substituent group and the substituentgroup represents an aliphatic group, an aromatic group, or aheterocyclic group. Z² is preferably the aliphatic group and furtherpreferably an alkyl group having a carbon number of one to six.

Q represents a hydrogen atom or a substituent group and the substituentgroup represents an aliphatic group, an aromatic group, or aheterocyclic group. Of these, Q is preferably a group comprisingnon-metallic atoms necessary to form five to eight-membered rings. Theabove-described five to eight-membered rings may be substituted, may besaturated rings or may have unsaturated bonds. Of these, the aromaticgroup and the heterocyclic group are particularly preferred. Thenon-metallic atoms include preferably a nitrogen atom, an oxygen atom, asulfur atom, and a carbon atom. Specific examples of such ringstructures include a benzene ring, a cyclopentane ring, a cyclohexanering, a cycloheptane ring, a cyclooctane ring, a cyclohexene ring, apyridine ring, a pyrimidine ring, a pyrazine ring, a pyridazine ring, atriazine ring, an imidazole ring, a benzimidazole ring, an oxazole ring,a benzoxazole ring, a thiazole ring, a benzothiazole ring, an oxanering, a sulfolane ring, a thiane ring, and the like.

Hydrogen atoms on the respective substituent groups as described ingeneral formula (1a) may be replaced. The substituent group includes thesubstituent groups described in general formula (1) and the groups andionic hydrophilic groups that exemplify G, R¹, and R².

The Hammett's substituent constant σ_(p) value used in this descriptionis hereinafter illustrated. The Hammett's rule is an empirical ruleproposed by L. P. Hammett in 1935 in order to discuss quantitatively theeffect of substituent groups on reaction or equilibrium of benzenederivatives, and the appropriateness thereof has been extensivelyadmitted now. For the substituent constants searched for the Hammett'srule, there are a σ_(p) value and a σ_(m) value and these values can beseen in many monographs, which are, for example, described in detail in“Lange's Handbook of Chemistry”, 12th edition, edited by J. A. Dean,1979 (Mc Graw-Hill) and “Kagaku-no-ryoiki” Special Number 122, pages 96to 103, 1979 (Nankodo). Although the respective substituent groups arelimited or described by Hammett's substituent constant σ_(p) values inthis invention, this does not mean, however, that values found in theabove-described monographs and known in literature are limited only toparticular substituent groups. It is a matter of course that even if thevalue of a substituent group is unknown in literature, the substituentgroup that will be involved in the range measured also is involved whenthe value is measured based on the Hammett's rule. Furthermore, althoughstructures that do not belong to benzene derivatives also are includedin general formula (1a) of this invention, the σ_(p) values are used asa measure showing the electron effect of substituent groups regardlessof positions of substitution. In this invention, the σ_(p) values areused in this sense.

Examples of electron-withdrawing groups having Hammett's substituentconstant σ_(p) values of 0.60 or higher include a cyano group, a nitrogroup, an alkylsulfonyl group (e.g., methylsulfonyl group), and anarylsulfonyl group (e.g., phenylsulfonyl group).

Examples of electron-withdrawing groups having Hammett's substituentconstant σ_(p) values of 0.45 or higher include, in addition to theabove-described groups, an acyl group (e.g., acetyl group), analkoxycarbonyl group (e.g., dodecyloxycarbonyl group), anaryloxycarbonyl group (e.g., m-chlorophenoxycarbonyl), an alkylsulfinylgroup (e.g., n-propylsulfinyl), an arylsulfinyl group (e.g.,phenylsulfinyl), a sulfamoyl group (e.g., N-ethylsulfamoyl,N,N-dimethylsulfamoyl), and a halogenated alkyl group (e.g.,trifluoromethyl).

Examples of electron-withdrawing groups having Hammett's substituentconstant σ_(p) values of 0.30 or higher include, in addition to theabove-described groups, an acyloxy group (e.g., acetoxy), a carbamoylgroup (e.g., N-ethylcarbamoyl), N,N-dibutylcarbamoyl), a halogenatedalkoxy group (e.g., trifluoromethyloxy), a halogenated aryloxy group(e.g., pentafluorophenyloxy), a sulfonyloxy group (e.g.,methylsulfonyloxy), a halogenated alkylthio group (e.g.,difluoromethylthio), aryl groups substituted by two or moreelectron-withdrawing groups having a values of 0.15 or higher (e.g.,2,4-dinitrophenyl, pentachlorophenyl), and a heterocycle (e.g.,2-benzoxazolyl, 2-benzothiazolyl, 1-phenyl-2-benzimidazolyl).

Specific examples of electron-withdrawing groups having σ_(p) values of0.20 or higher include halogen atoms in addition to the above-describedgroups.

About the combination of substituent groups particularly preferred forazo dyes represented by the above-described general formula (1), R⁵ andR⁶ are preferably a hydrogen atom, an alkyl group, an aryl group, aheterocyclic group, a sulfonyl group, and an acyl group, furtherpreferably the hydrogen atom, the aryl group, the heterocyclic group,and the sulfonyl group, and most preferably the hydrogen atom, the arylgroup, and the heterocyclic group. However, R⁵ and R⁶ can not behydrogen atoms at the same time.

G is preferably a hydrogen atom, a halogen atom, an alkyl group, ahydroxyl group, an amino group, and an acylamino group, more preferablythe hydrogen atom, the halogen atom, the amino group, the acylaminogroup, and most preferably the hydrogen atom, the amino group, and theacylamino group.

A is preferably a pyrazole ring, an imidazole ring, an isothiazole ring,a thiadiazole ring, and a benzothiazole ring, further preferably thepyrazole ring and the isothiazole ring, and most preferably the pyrazolering.

B¹ and B² each is ═CR¹— and —CR²═, and R¹ and R² each are preferably ahydrogen atom, an alkyl group, a halogen atom, a cyano group, acarbamoyl group, a carboxyl group, a hydroxyl group, an alkoxy group,and an alkoxycarbonyl group and more preferably the hydrogen atom, thealkyl group, the carboxyl group, the cyano group, and the carbamoylgroup.

About preferred combinations of substituent groups on compoundsrepresented by the above-described general formula (1), a compound inwhich at least one of various substituent groups thereon is a preferredgroup as described above is preferred, a compound in which more ofvarious substituent groups thereon are preferred groups as describedabove is more preferred, and a compound in which all of varioussubstituent groups thereon are the preferred groups as described aboveis most preferred.

Although specific examples of azo dyes represented by theabove-described general formula (1) are shown in the following table 1to table 13, the azo dyes used in this invention are not limited by theexamples as shown below.

Dye R₁ R₂ R₃ a-1

a-2

a-3

a-4

a-5

Dye R₁ R₂ R₃ a-6

a-7

a-8

a-9

C₈H₁₇(t) a-10

Dye R₁ R₂ R₃ R₄ a-11

a-12

a-13

a-14

a-15

a-16

a-17

Dye R₁ R₂ R₃ R₄ a-18

a-19

—SO₂CH₃

a-20

—COCH₃ C₈H₁₇(t) C₈H₁₇(t) a-21

—SO₂CH₃

C₈H₁₇(t) a-22

H

a-23

H

a-24

H

a-25

Dye R₁ R₂ a-26

a-27

a-28

a-29

a-30

a-31

Dye R₃ R₄ a-26

a-27

a-28

a-29

a-30

C₈H₁₇(t) a-31

Dye R₁ R₂ a-32

a-33

a-34

a-35

Dye R₃ R₄ a-32

a-33

a-34

a-35

Dye R₁ R₂ a-36

a-37

a-38

a-39

a-40

Dye R₃ R₄ a-36

a-37

a-38

a-39

a-40

Dye R₁ R₂ R₃ R₄ R₅ R₆ a-41

CN

H CONH₂ SO₂CH₃ a-42

Br

COOEt H

a-43

SO₂CH₃

CONH₂ H

a-44

CN

H H

a-45

Br

H CONH₂

a-46

CN

CH₃ H

Dye R₇ R₈ a-41

a-42 C₈H₁₇(t) COCH₃ a-43

a-44

SO₂CH₃ a-45

a-46

Dye R₁ R₂ R₃ R₄ R₅ R₆ b-1 CH₃ CH₃ CN H

b-2 CH₃ CH₃ CN H

b-3 CH₃ CH₃ CONH₂ H

b-4 CH₃ CH₃ H H

b-5 CH₃ H CN H

Dye R₁ R₂ R₃ R₄ R₅ R₆ b-6 CH₃ CH₃ H

b-7 CH₃ CH₃ H

b-8 CH₃ H H SO₂CH₃

Dye R₁ R₂ R₃ R₄ R₅ R₆ c-1 —SCH₃ CH₃ CN H C₈H₁₇(t)

c-2

H CONH₂ H

c-3

CH₃ H

c-4 —CH₃ CH₃ H

c-5

H H

C₈H₁₇(t)

Dye R₁ R₂ R₃ R₄ R₅ R₆ d-1 Me CH₃ CN H

d-2 Me CH₃ CN H

d-3 Me H H

d-4 Ph CH₃ CONH₂ H

d-5 Ph CH₃ H

Dye R₁ R₂ R₃ R₄ R₅ R₆ e-1 5-Cl CH₂ CONH₂ H C₈H₁₇(t) C₈H₁₇(t) e-25,6-diCl H H

e-3 5,6-diCl CH₃ H

COCH₃ e-4 5-CH₃ H CN H

e-5 5-NO₂ CH₃ H SO₂CH₃

In the magenta dye having the above-described azo group used in thisinvention, the oxidation potential of the dye is 1.0 V or more positivevs SCE, preferably 1.1 V or more positive vs SCE, and particularlypreferably 1.2 V or more positive vs SCE in the aqueous medium of ink.As a means to elevate the potential, the preferred required conditionsof constitution as described above are selected, that is, selection of adye structure having the chromophore represented by (heterocycleA)-N═N-(heterocycle B), selection of an azo dye in which an aromaticnitrogen-containing six-membered heterocycle links directly to at leastone side of the azo group as a coupling component, selection of an azodye having as an auxochrome a structure containing an aromatic ringamino group or a heterocyclic amino group, and furthermore removal ofthe α-hydrogen of an azo dye. Particularly, the dyes represented by theabove-described general formula (1) develop higher potentials. Specificexamples are described in JP Application No. 2001-254878.

The method for measuring the oxidation potential meant herein is ameasuring method where an SCE (standard saturation calomel electrode) isused as a reference electrode in an aqueous solution or a water-mixedsolvent system containing a dye dissolved, and various methods can beutilized including DC polarography where a graphite electrode or aplatinum electrode is used as an action electrode, polarographydepending upon a titration mercury electrode, cyclic voltammetry (CV),rotating ring desk electrode method, and combshaped electrode method.The oxidation potential is determined as a value to an SCE (standardsaturation calomel electrode) by use of the above-described measuringmethods wherein a specimen is dissolved in concentration of 1×10⁻⁴ to1×10⁻⁶ mol·dm⁻³ in a solvent such as dimethylformamide or acetonitrilethat contains sodium perchlorate or tetrapropylammonium perchlorate as asupporting electrolyte. The supporting electrolyte and solvent used canbe appropriately selected depending upon the oxidation potential orsolubility of a specimen. The supporting electrolyte and solvent usableare described in Akira Fujishima et al., “Denkikagaku Sokuteiho”, pages101 to 118 (1984, Published by Gihodo Shuppan Co.).

Although the value of oxidation potential may be biased by several tensmV in some cases under the influence of liquid junction potential orsolution resistance of a sample solution, the reproducibility of apotential value measured can be ensured by correcting the value by useof a standard sample (e.g., hydroquinone), and furthermore the samemeasured value can be obtained by use of any of the above-describedmeans to measure the potential.

For the azo dyes having oxidation potentials of 1.0 V or more positivevs SCE, there is a rate constant of forced fading due to an ozone gas asanother standard of oxidation resistance and the rate constants offorced fading of preferred azo dyes are 5×10⁻² [hour⁻¹] or less,preferably 3×10⁻² [hour⁻¹] or less, and more preferably 1.5×10⁻²[hour⁻¹] or less.

In measurement of the rate constants of forced fading due to an ozonegas, a coloring region of 0.90 to 1.10 in reflection density measuredthrough a status A filter, which is color of a main spectral absorptionregion of the ink of an image obtained by printing on a reflection-typeimage-receiving medium by use of the ink, is selected as an initialdensity point and this initial density is taken as a starting density(=100 percent). This image is allowed to fade in an ozone fadeometer inwhich the ozone concentration is maintained at 5 mg/liter all the time,a time taken until the density reaches 80 percent of the initial densityis measured, and the reciprocal calculated of this time [hour⁻¹] istaken as the rate constant of fading reaction on the supposition thatthe relation between the fading density and the time obeys the rateequation of first order reaction. Accordingly, although the rateconstant of fading reaction found is a rate constant of fading reactionin the coloring region where printing is carried out by use of the saidink, in the present description, this value is used as a rate constantof fading reaction of ink.

Image patches for test usable include a patch of JIS cord 2223 where ablack square sign is printed, a stepwise color patch of Macbeth chart,and further an arbitrary stairstep density patch by which measured areasare obtained.

The reflection density of a reflection image (stepwise color patch)printed for measurement is a density determined with the aid ofmeasuring light passing through a status A filter with a densitometermeeting international standard ISO 5-4 (a geometric condition ofreflection density).

A test chamber for measuring the rate constant of forced fading reactiondue to an ozone gas has therein an ozone generator that can maintain thechamber at an ozone gas concentration of 5 mg/liter all the time (e.g.,a high voltage spark system where an alternating voltage is applied todried air), and the exposure temperature is controlled to 25° C.

This rate constant of forced fading is an index of susceptibility tooxidation under an oxidative atmosphere of environment such asphotochemical smog, automobile exhaust, organic fumes from coatedsurfaces of furniture and carpets, and gas generated from the inside ofa picture frame in a bright room and is an index where the ozone gasrepresents these oxidative atmospheres.

Subsequently, the color hue of magenta ink is described. The magenta inkis excellent in view of color hue since the λ_(max) lies in 500 to 580nm, and it is further preferable that the half band width of the maximumabsorption wavelength is small at the long wave side and short waveside, that is, the absorption is sharp. This is specifically describedin JP-A-2002-309133. The introduction of a methyl group into the αposition enables sharpness of the absorption to develop.

[Phthalocyanine Dye]

Properties required by the ink for ink jet recording are to be excellentin both light resistance and ozone resistance and small in change ofcolor hue and surface conditions (The generation of bronzing and theseparation of dye are difficult) About the light resistance (OD 1.0), ata condition of Xe 1.1 W/m (intermittent condition) on theimage-receiving paper for Epson PM photograph, it is preferable thatlight resistance per triacetylcellulose (TAC) filter is 90 percent ormore in residual ratio of dyestuff in three days. Furthermore, it ispreferable that the residual ratio of dyestuff is 85 percent or more in14 days.

About the ozone resistance, in a monochromatic site printed so that acyan reflection density is from 0.9 to 1.1 in the status A filter by useof an ink (cyan) monochrome, it is preferable that the residual ratio ofdyestuff (density after fading/initial density×100) is 60 percent ormore when kept in an atmosphere of 5-ppm ozone for 24 hr. In the ozoneresistance, it is further preferable that the residual ratio of dyestuffis 70 percent or more in a day and particularly preferable that theresidual ratio of dyestuff is 80 percent or more in a day. Furthermore,in five days, the residual ratio of dyestuff is preferably 25 percent ormore, the residual ratio of dyestuff is more preferably 40 percent ormore, and the residual ratio of dyestuff is particularly preferably 50percent or more. Samples having different coating amounts are preparedwith GTC and the amounts of Cu element contained in dyes are measuredwith the aid of fluorescent X-rays.

The Cu ion exists as a phthalic salt owing to decomposition of aphthalocyanine dye. It is preferable to keep the converted amount of theCu ion existing in practical prints at 10 mg/m² or less. About theamount of Cu effused from prints, a cyan solid image having a convertedamount of Cu ion of 20 mg/m² or less is formed on the whole surface andis subjected to ozone fading at the above-described conditions for ozoneresistance, and then the amount of the ion effused in water is measured.Before fading, all Cu compounds are trapped in image-receivingmaterials. It is preferable that the amount of Cu ion effused in wateris 20 percent or less of the total dye.

This invention has found that the phthalocyanine dyes having theabove-described properties can be achieved by 1) elevating the oxidationpotential, 2) elevating an associating property, 3) introducing anassociation-promoting group and strengthening a hydrogen bonding on π-πstacking, and 4) introducing no substituent group into the α-position,that is, to facilitate stacking.

The phthalocyanine dye used for conventional inks for ink jet recordingis derived from the sulfonation of an unsubstituted phthalocyanine andconsequently forms a mixture of compounds in which the number andposition of the substituent group can not be identified and on the otherhand, the feature of the ink for ink jet recording of the invention isto use a phthalocyanine dye in which the number and position of thesubstituent group can be identified. The first structural feature of thedye is to be a water-soluble phthalocyanine dye obtained without goingthrough the sulfonation of an unsubstituted phthalocyanine. The secondstructural feature of the dye is to have electron-withdrawing groups onthe β-positions of the benzene rings of phthalocyanine, and particularlypreferably to have electron-withdrawing groups on the β-positions of allbenzene rings. Useful dyes are specifically those substituted bysulfonyl groups (JP Application Nos. 2001-47013 and 2001-190214), thosesubstituted by all the sulfamoyl groups (JP Application Nos. 2001-24352and 2001-189982), those substituted by heterocyclic sulfamoyl groups (JPApplication Nos. 2001-96610 and 2001-190216), those substituted byheterocyclic sulfonyl groups (JP Application Nos. 2001-76689 and2001-190215), those substituted by particular sulfamoyl groups (JPApplication No. 2001-57063), those substituted by carbonyl groups (JPApplication No. 2002-012869), those having particular substituent groupsfor improvement in solubility and stability of ink or as a measure ofbronzing, specifically those having an asymmetric carbon atom (JPApplication No. 2002-012868) and those having Li salts (JP ApplicationNo. 2002-012864).

The first feature of properties of the phthalocyanine dyes used for theinks for ink jet recording of this invention is to have a high oxidationpotential. The oxidation potential is preferably 1.0 V or more positive,further preferably 1.1 V or more positive, and most preferably 1.2 V ormore positive. The second feature of properties thereof is to have astrong associating property. Specific examples include oil-soluble dyeswhose association is prescribed (JP Application No. 2001-64413) andwater-soluble dyes whose association is prescribed (JP Application No.2001-117350).

In the relation between the number of associative groups and performance(absorbance of ink), the introduction of the associative groups promotesdecrease in absorbance and shift Of λ_(max) to shorter wavelength evenin a dilute solution. Furthermore, in the relation between the number ofassociative groups and performance (reflection OD on Epson PM 920image-receiving paper), as the number of associative groups increases,the reflection OD decreases in the same ion strength. That is, it isthought that the association proceeds on the image-receiving paper. Inthe relation between the number of associative groups and performance(ozone resistance, light resistance), as the number of associativegroups increases, the ozone resistance is improved. Dyes having a numberof the associative groups also tend to improve the light resistance. Inorder to impart the ozone resistance, it is necessary to impart theabove-described substituent groups X's (represents X₁ to X₄ etc.) Sincethe reflection OD and fastness consist in a relation of trade-off, it isnecessary to elevate the light resistance without weakening theassociation.

Modes of the preferred ink of the invention are as follows.

1) A cyan ink having a residual color ratio of 90 percent or more inthree days as light resistance at a condition of Xe 1.1 W/m(intermittent condition) on the image-receiving paper for Epson PMphotograph in the presence of a TAC filter.

2) In a monochromatic site printed by use of the ink (cyan) monochromeso that the cyan reflection density in status A filter becomes from 0.9to 1.1, a cyan ink having a residual ratio of dyestuff (density afterfading/initial density×100) of 60 percent (preferably 80 percent) ormore when kept in an ozone atmosphere of 5 ppm for 24 hr.

3) A cyan ink where an amount of Cu ion effused into water is 20 percentor less of the total dye after carrying out ozone fading at theconditions of the above-described 2).

4) A cyan ink where permeation of the ink into particularimage-receiving paper can be achieved until 30 percent or more of theupper portion of the image-receiving layer.

Phthalocyanine dyes contained in the ink for ink jet recording of thisinvention are preferably water-soluble dyes having oxidation potentialsmore positive than 1.0, more preferably those further satisfying theabove-described conditions in the resistance to ozone gas, and of thesedyes, further preferably phthalocyanine dyes represented by theabove-described general formula (I).

Although the phthalocyanine dyes are known as fast dyes, it is knownthat the dyes are inferior in resistance to ozone gas deteriorates whenused as dyes for ink jet recording.

In order to decrease the reactivity to the ozone that is anelectrophile, in this invention, the oxidation potential is adjusted toa value more positive than 1.0 V (vs SCE) by introducingelectron-withdrawing groups into a phthalocyanine skeleton. The morepositive oxidation potential is more preferred, the dyes havingoxidation potentials more positive than 1.1V (vs SCE) are morepreferred, and those having oxidation potentials more positive than 1.2V (vs SCE) are most preferred.

The traders concerned can readily measure the values of oxidationpotential (E_(ox)). The methods are described, for example, in P.Delahay, “New Instrumental Methods in Electrochemistry”, (1954,Published by Interscience Publishers Co.), A. J. Bard, et al.,“Electrochemical Methods”, (1980, Published by John Wiley & Sons, Co.),and Akira Fujishima, et al., “Denkikagaku Sokuteiho”, (1984, Publishedby Gihodo Schuppansha), and the like.

Specifically, the oxidation potential is measured as a value to SCE(standard saturation calomel electrode) by cyclic voltammetry or DCpolarography wherein a specimen is dissolved in concentration of 1×10⁻⁴to 1×10⁻⁶ mole/liter in a solvent such as dimethylformamide oracetonitrile that contains a supporting electrolyte such as sodiumperchlorate or tetrapropylammonium perchlorate. Although this value maybe biased in some cases by several tens mV under the influence of liquidjunction potential, solution resistance of a sample solution, and thelike, it is possible to ensure the reproducibility of the potential withthe aid of a standard sample (e.g., hydroquinone).

In order to prescribe the potential without hesitation, in thisinvention, the value (vs SCE) measured by DC polarography indimethylformamide containing 0.1 mole·dm⁻³ of tetrapropylammoniumperchlorate as a supporting electrolyte (the concentration of a dye:0.001 mole·dm⁻³) is taken as the oxidation potential of the dye.

The value of E_(OX) (oxidation potential) represents the feasibility totransfer an electron from a sample to an electrode and a greater value(a more positive oxidation potential) makes it more difficult totransfer the electron from the sample to the electrode, in other words,makes oxidation more difficult. In relation to the structure of acompound, the introduction of an electron-withdrawing group makes theoxidation potential more positive and the introduction of anelectron-donating group makes it lower. In order to reduce thereactivity to ozone that is an electrophile, in this invention, it isdesirable to make the oxidation potential more positive by introducingthe electron-withdrawing groups into the skeleton of phthalocyanine.Accordingly, by utilizing the Hammett's substituent constant σ_(p) valuewhich are a measure of an electron-withdrawing property andelectron-donating property of the substituent group, it can be said thatthe introduction of a substituent group having a high σ_(p) value suchas sulfinyl group, sulfonyl group, or sulfamoyl group makes it possibleto elevate the oxidation potential.

For the reason of adjusting this potential, use of the phthalocyaninedyes represented by the above-described general formula (I) ispreferred.

It is evident that the phthalocyanine dyes having the above-describedoxidation potentials are cyan dyes excellent in both light resistanceand ozone resistance because the dyes satisfy the above-describedconditions of the light resistance and ozone resistance.

The phthalocyanine dyes used in this invention (preferably, thephthalocyanine dyes represented by general formula (I)) are hereinafterillustrated in detail.

In general formula (I), X₁, X₂, X₃, and X₄ each independently represent—SO-Z, —SO₂-Z, —SO₂NR1R2, a sulfo group, —CONR1R2, or —CO₂R1. Of thesesubstituent groups, —SO-Z, —SO₂-Z, —SO₂NR1R2, and —CONR1R2 arepreferred, particularly —SO₂-Z and —SO₂NR1R2 are preferred, and —SO₂-Zis most preferred. When any of a₁ to a₄ representing the number ofsubstituent groups represents a number of two or more, X₁ to X₄ that mayexist in plurality may be the same or different and each independentlyrepresent any of the above-described substituent groups. Furthermore,X₁, X₂; X₃, and X₄ can be quite the same substituent group,respectively, or for example, X₁, X₂, X₃, and X₄ all may be —SO₂-Z, butdifferent in Z, respectively, that is, they belong to the same kind, butmay be partly different substituent groups where the respective Z's aredifferent, or may contains substituent groups different from each other,for example, —SO₂-Z and —SO₂NR1NR2.

The above-described Z's each independently represent a substituted orunsubstituted alkyl group, a substituted or unsubstituted cycloalkylgroup, a substituted or unsubstituted alkenyl group, a substituted orunsubstituted aralkyl group, a substituted or unsubstituted aryl group,or a substituted or unsubstituted heterocyclic group. The substituted orunsubstituted alkyl group, the substituted or unsubstituted aryl group,and the substituted or unsubstituted heterocyclic group are preferredand of these, the substituted alkyl group, the substituted aryl group,and the substituted heterocyclic group are most preferred.

The above-described R1 and R2 each independently represent a hydrogenatom, a substituted or unsubstituted alkyl group, a substituted orunsubstituted cycloalkyl group, a substituted or unsubstituted alkenylgroup, a substituted or unsubstituted aralkyl group, a substituted orunsubstituted aryl group, or a substituted or unsubstituted heterocyclicgroup. Of these, the hydrogen atom, the substituted or unsubstitutedalkyl group, the substituted or unsubstituted aryl group, and thesubstituted or unsubstituted heterocyclic group are preferred and ofthese, the hydrogen atom, the substituted alkyl group, the substitutedaryl group, and the substituted heterocyclic group are furtherpreferred. However, it is unpreferable that both R1 and R2 are hydrogenatoms.

The substituted or unsubstituted alkyl groups that R1, R2, and Zrepresent preferably are alkyl groups having a carbon number of one to30. Particularly, branched alkyl groups are preferred for the reason ofheightening the solubility of dye and the stability of ink, and thosecontaining an asymmetric carbon therein (used as racemic bodies) areparticularly preferred. Examples of the substituent group include thesame as the substituent groups that Z, R1, R2, Y₁, Y₂, Y₃, and Y₄ canfurther have as described later. Of these, a hydroxyl group, an ethergroup, an ester group, a cyano group, an amido group, and a sulfonamidogroup are particularly preferred because of heightening the associatingproperty of dye and improving the fastness thereof. In addition, it alsois preferred to contain a halogen atom and an ionic hydrophilic group.The carbon number of the alkyl group contains no carbon number of thesubstituent group thereon and this is similarly applied to other groupsalso.

The substituted or unsubstituted cycloalkyl group that R1, R2, and Zrepresent preferably includes cycloalkyl groups having a carbon numberof five to 30. The groups containing an asymmetric carbon therein (usedas racemic bodies) are particularly preferred for the reason ofheightening the solubility of dye and the stability of ink. Examples ofthe substituent group include the same as the substituent groups that Z,R1, R2, Y₁, Y₂, Y₃, and Y₄ can have further as described later. Ofthese, a hydroxyl group, an ether group, an ester group, a cyano group,an amido group, and a sulfonamido group are particularly preferredbecause of heightening the associating property of dye and improving thefastness thereof. In addition, the examples can include a halogen atomand an ionic hydrophilic group also.

The substituted or unsubstituted alkenyl group that R1, R2, and Zrepresent preferably includes alkenyl groups having a carbon number oftwo to 30. Particularly, a branched alkenyl group is preferred and agroup containing an asymmetric carbon therein (used as a racemic body)is particularly preferred for the reason of heightening the solubilityof dye and improving the stability of ink. Examples of the substituentgroup include the same as the substituent groups that Z, R1, R2, Y₁, Y₂,Y₃, and Y₄ can further have as described later. Of these, a hydroxylgroup, an ether group, an ester group, a cyano group, an amido group,and a sulfonamido group are particularly preferred because ofheightening the associating property of dye and improving the fastnessthereof. In addition, the examples can include a halogen atom and anionic hydrophilic group also.

The substituted or unsubstituted aralkyl group that R1, R2, and Zrepresent preferably includes aralkyl groups having a carbon number ofseven to 30. Particularly, for the reason of heightening the solubilityof dye and the stability of ink, a branched aralkyl group is preferredand a group containing an asymmetric carbon therein (used as racemicbodies) is particularly preferred. Examples of the substituent groupinclude the same as the substituent groups that Z, R1, R2, Y₁, Y₂, Y₃,and Y₄ can further have as described layer. Of these, a hydroxyl group,an ether group, an ester group, a cyano group, an amido group, asulfonamide group are particularly preferred because of heightening theassociating property of dye and improving the fastness thereof. Inaddition, the examples can include a halogen atom and an ionichydrophilic group also.

The substituted or unsubstituted aryl group that R1, R2, and Z representpreferably includes aryl groups having a carbon number of six to 30.Examples of the substituent group include the same as the substituentgroups that Z, R1, R2, Y₁, Y₂, Y₃, and Y₄ can further have as describedlater. Of these, electron-withdrawing groups are particularly preferredbecause of heightening the oxidation potential of dye and improving thefastness thereof. The electron-withdrawing groups are groups havingpositive Hammett's substituent constant σ_(p) values. Of these, ahalogen atom, a heterocyclic group, a cyano group, a carboxyl group, anacylamino group, a sulfonamido group, a sulfamoyl group, a carbamoylgroup, a sulfonyl group, an imido group, an acyl group, a sulfo group,and a quaternary ammonium group are preferred, and the cyano group, thecarboxyl group, the sulfamoyl group, the carbamoyl group, the sulfonylgroup, the imido group, the acyl group, the sulfo group, and thequaternary ammonium group are further preferred.

The heterocyclic group that R1, R2, and Z represent preferably is of afive-membered or six-membered ring, which may further be condensed.Furthermore, the group can be an aromatic heterocylic group or anon-aromatic heterocyclic group. Although the heterocyclic grouprepresented by R1, R2, and Z is exemplified below in the form ofheterocycle where positions of substitution are omitted, the positionsof substitution are not limited, for example, pyridine can besubstituted at the 2-, 3-, and 4-positions. Examples of the heterocyclicgroup include Pyridine, pyrazine, pyrimidine, pyridazine, triazine,quinoline, isoquinoline, quinazoline, cinnoline, phthalazine,quinoxaline, pyrrole, indole, furan, benzofuran, thiophene,benzothiophene, pyrazole, imidazole, benzimidazole, triazole, oxazole,benzoxazole, thiazole, benzothiazole, isothiazole, benzisothiazole,thiadiazole, isooxazole, benzisooxazole, pyrrolidine, piperidine,piperazine, imidazolidine, thiazoline, and the like. Of these, thearomatic heterocyclic groups are preferred and the preferred examples,if they are exemplified similarly to the preceding examples, includepyridine, pyradine, pyrimidine, pyridazine, triazine, pyrazole,imidazole, benzimidazole, triazole, thiazole, benzothiazole,isothiazole, benzisothiazole, thiadiazole, and the like. These groupsmay have substituent groups and examples of the substituent groupsinclude the same as the substituent groups that Z, R1, R2, Y₁, Y₂, Y₃,and Y₄ can further have as described later. Preferred substituent groupsare identical with the above-described substituent groups on aryl groupsand more preferred substituent groups are identical with the morepreferred substituent groups on aryl groups as described above,respectively.

Y₁, Y₂, Y₃, and Y₄ each independently include a hydrogen atom, a halogenatom, an alkyl group, a cycloalkyl group, an alkenyl group, an aralkylgroup, an aryl group, a heterocyclic group, a cyano group, a hydroxylgroup, a nitro group, an amino group, an alkylamino group, an alkoxygroup, an aryloxy group, an acylamino group, an arylamino group, anureido group, a sulfamoylamino group, an alkylthio group, an arylthiogroup, an alkoxycarbonylamino group, a sulfonamido group, a carbamoylgroup, a sulfamoyl group, a sulfonyl group, an alkoxycarbonyl group, aheterocyclic oxy group, an azo group, an acyloxy group, a carbamoyloxygroup, a silyloxy group, an aryloxycarbonyl group, anaryloxycarbonylamino group, an imido group, a heterocyclic thio group, asulfolyl group, an acyl group, a carboxyl group, or a sulfo group, andthe respective groups may further have substituent groups.

Of these groups, the hydrogen atom, the halogen atom, the alkyl group,the aryl group, the cyano group, the alkoxy group, the amido group, theureido group, the sulfonamido group, the carbamoyl group, the sulfamoylgroup, the alkoxycarbonyl group, the carboxyl group, and the sulfo groupare preferred, particularly the hydrogen atom, the halogen atom, thecyano group, the carboxyl group, and the sulfo group are preferred, andthe hydrogen atom is most preferred.

When Z, R1, R2, Y₁, Y₂, Y₃, and Y₄ are groups that can have furthersubstituent groups, it is possible to have further the followingsubstituent groups.

Examples of the substituent groups include straight chain or branchedchain alkyl groups having a carbon number of one to 12, straight chainor branched chain aralkyl groups having a carbon number of seven to 18,straight chain or branched chain alkenyl groups having a carbon numberof two to 12, straight chain or branched chain alkynyl groups having acarbon number of two to 12, straight chain or branched chain cycloalkylgroups having a carbon number of three to 12, and straight chain orbranched chain cycloalkenyl groups having a carbon number of three to 12(Of these groups, groups having branched chains are preferred for thereason of improving the solubility of dye and the stability of ink, andthe groups containing asymmetric carbons are particularly preferred.Specific examples of the respective groups as described above: forexample, methyl, ethyl, propyl, isopropyl, sec-butyl, t-butyl,2-ethylhexyl, 2-methylsulfonylethyl, 3-phenoxypropyl, trifluoromethyl,and cyclopentyl), a halogen atom (e.g., chlorine atom and bromine atom),an aryl group (e.g., phenyl, 4-t-butylphenyl, and 2,4-di-t-amylphenyl),a heterocyclic group (e.g., imidazolyl, pyrazolyl, triazolyl, 2-furyl,2-thienyl, 2-pyrimidinyl, and 2-benzotiazolyl), a cyano group, ahydroxyl group, a nitro group, a carboxyl group, an amino group, analkyloxy group (e.g., methoxy, ethoxy, 2-methoxyethoxy, and2-methanesulfonylethoxy), an aryloxy group (e.g., phenoxy,2-methylphenoxy, 4-t-butylphenoxy, 3-nitrophenoxy,3-t-butoxycarbamoylphenoxy, and 3-methoxycarbamoyl), an acylamino group(e.g., acetamido, benzamido, and4-(3-t-butyl-4-hydroxyphenoxy)butaneamido), an alkylamino group (e.g.,methylamino, butylamino, diethylamino, and methylbutylamino), an anilinogroup (e.g., phenylamino and 2-chloroanilino), an ureido group (e.g.,phenylureido, methylureido, and N,N-dibutylureido), a sulfamoylaminogroup (e.g., N,N-dipropylsulfamoylamino), an alkylthio group (e.g.,methylthio, octylthio and 2-phenoxyethylthio), an arylthio group (e.g.,phenylthio, 2-butoxy-5-t-octylphenylthio, and 2-carboxyphenylthio), analkyloxycarbonylamino group (e.g., methoxycarbonylamino), a sulfonamidogroup (e.g., methanesulfonamido, benzenesulfonamido, andp-toluenesulfonamido), a carbamoyl group (e.g., N-ethylcarbamoyl andN,N-dibutylcarbamoyl), a sulfamoyl group (e.g., N-ethylsulfamoyl,N,N-dipropylsulfamoyl, and N-phenylsulfamoyl), a sulfonyl group (e.g.,methanesulfonyl, octanesulfonyl, benzenesulfonyl, and toluenesulfonyl),an alkyloxycarbonyl group (e.g., methoxycarbonyl and butoxycarbonyl), aheterocyclic oxy group (e.g., 1-phenyltetrazole-5-oxy and2-tetrahydropyranyloxy), an azo group (e.g., phenylazo,4-methoxyphenylazo, 4-pivaloylaminophenylazo, and2-hydroxy-4-propanoylphenylazo), an acyloxy group (e.g., acetoxy), acarbamoyloxy group (e.g., N-methylcarbamoyloxy andN-phenylcarbamoyloxy), a silyloxy group (e.g., trimethylsilyloxy anddibutylmethylsilyloxy), an aryloxycarbonylamino group (e.g.,phenoxycarbonylamino), an imido group (e.g., N-succinimido andN-phthalimido), a heterocyclic thio group (e.g., 2-benzothiazolylthio,2,4-di-phenoxy-1,3,5-triazole-6-thio, and 2-pyridylthio), a sulfinylgroup (e.g., 3-phenoxypropylsulfinyl), a phosphonyl group (e.g.,phenoxyphosphonyl, octyloxyphosphonyl, and phenylphosphonyl), anaryloxycarbonyl group (e.g., phenoxycarbonyl), an acyl group (e.g.,acetyl, 3-phenylpropanoyl, and benzoyl), and anionic hydrophilic group(e.g., carboxyl group, sulfo group, phosphono group, and quaternaryammonium group).

When the phthalocyanine dyes represented by the above-described generalformula (I) are water-soluble, it is preferable that the dyes have anionic hydrophilic group. The ionic hydrophilic group includes a sulfogroup, a carboxyl group, a phosphono group, an ammonium group, and thelike. The ionic hydrophilic group is preferably the carboxyl group, thephosphono group, and the sulfo group and particularly preferably thecarboxyl group and the sulfo group. The carboxyl group, the phosphonogroup, and the sulfo group may be in the form of salt and examples ofcounter ions to form the salt include an ammonium ion, an alkali metalion (e.g., lithium ion, sodium ion, and potassium ion), and an organiccation (e.g., tetramethylammonium ion, tetramethylquanidinium ion, andtetramethylphosphonium). Of the counter ions, the alkali metal salt ispreferred and a lithium salt is particularly preferred because ofheightening the solubility of dye and improving the stability of ink.

About the number of ionic hydrophilic groups, it is preferred to containat least two ionic hydrophilic groups in a molecule of thephthalocyanine dye, and it is particularly preferred to contain at leasttwo sulfo groups and/or carboxyl groups.

a₁ to a₄ and b₁ to b₄ represent the number of substituent groups X₁ toX₄ and Y₁ to Y₄, respectively. a₁ to a₄ each independently represent aninteger of zero to four, but all thereof can not be zero at the sametime. b₁ to b₄ each independently represent an integer of zero to four.When any of a₁ to a₄ and b₁ to b₄ is an integer of two or more, it meansthat any of X₁ to X₄ and Y₁ to Y₄ exists in plurality and then they maybe the same or different.

a₁ and b₁ meet a relation of a₁+b₁=4. Combinations of a₁ representing 1or 2 and b₁ representing 3 or 2 are particularly preferred and of these,the combination of a₁ representing 1 and b₁ representing 3 is mostpreferred.

The respective combinations of a₁ and b₁, a₁ and b₁, and a₁ and b₁ alsohave relation similar to the combination of a₁ and b₁ and preferredcombinations thereof also are similar.

M represents a hydrogen atom, a metallic element, or an oxide, ahydroxide, or a halide thereof.

Preferred M includes, in addition to the hydrogen atom, as the metallicelement Li, Na, K, Mg, Ti, Zr, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Co, Ni, Ru,Rh, Pd, Os, Ir, Pt, Cu, Ag, Au, Zn, Cd, Hg, Al, Ga, In, Si, Ge, Sn, Pb,Sb, Bi, and the like. The oxide preferably includes VO, GeO, and thelike.

The hydroxide preferably includes Si(OH)₂, Cr(OH)₂, Sn(OH)₂, and thelike. Furthermore, the halide includes AlCl, SiCl₂, VCl, VCl₂, VOCl,FeCl, GaCl, ZrCl, and the like. Of these, Cu, Ni, Zn, Al, and the likeare preferred and Cu is most preferred.

Pc (phthalocyanine ring) may form a dimer (e.g., Pc-M-L-M-Pc) or atrimer through L (divalent connecting group), and then the respectiveM's may be the same or different.

The divalent connecting group represented by L preferably includes anoxy group —O—, a thio group —S—, a carbonyl group —CO—, a sulfonyl group—SO₂—, an imino group —NH—, a methylene group —CH₂—, and a group formedby combining these groups.

About combinations of preferred substituent groups on the compoundsrepresented by the above-described general formula (I), a compound inwhich at least one of various substituent groups is a preferred group asdescribed above is preferred, a compound in which more of varioussubstituent groups are preferred groups as described above is morepreferred, and a compound in which all of various substituent groups arepreferred groups as described above is most preferred.

Of the phthalocyanine dyes represented by the above-described generalformula (I), the phthalocyanine dyes having structures represented bythe above-described general formula (II) are further preferred. Thephthalocyanine dyes represented by general formula (II) of thisinvention are hereinafter described in detail.

In the above-described general formula (II), X₁₁ to X₁₄ and Y₁₁ to Y₁₈have the same meanings as X₁ to X₄ and Y₁ to Y₄, and preferred examplesthereof also are similar. Furthermore, M₁ has the same meaning as M ingeneral formula (I) and preferred examples also are similar.

In general formula (II), a₁₁ to a₁₄ each independently represent aninteger of one or two, preferably 4≦a₁₁+a₁₂+a₁₃+a₁₄≦6 is satisfied, andthe case of a₁₁=a₁₂=a₁₃=a₁₄=1 is particularly preferred.

X₁₁, X₁₂, X₁₃, and X₁₄ can be the very same substituent group,respectively, or, for example, all X₁₁, X₁₂, X₁₃, and X₁₄ are —SO₂-Z,but different in Z, that is, may be substituent groups of the same kindbut substituent groups different partly, or may be substituent groupsdifferent from one another, for example, —SO₂Z and —SO₂NR1R2.

About the phthalocyanine dyes represented by general formula (II), thecombinations of particularly preferred substituent groups are asfollows.

X₁₁ to X₁₄ each independently are preferably —SO-Z, —SO₂-Z, —SO₂NR1R2,or —CONR1R2, particularly preferably —SO₂-Z or —SO₂NR1R2, and mostpreferably —SO₂-Z.

Z's each independently are preferably a substituted or unsubstitutedalkyl group, a substituted or unsubstituted aryl group, and asubstituted or unsubstituted heterocyclic group and of these, thesubstituted alkyl group, the substituted aryl group, and the substitutedheterocyclic group are most preferred. Particularly, the substituentgroup containing an asymmetric carbon therein (used as a racemic body)is preferred for the reason of increasing the solubility of dye and thestability of ink. Furthermore, it is preferable that the substituentgroups contain therein a hydroxyl group, an ether group, an ester group,a cyano group, an amido group, and a sulfonamido group for the reason ofheightening the associating property and improving the fastness.

R1 and R2 each independently are preferably a hydrogen atom, asubstituted or unsubstituted alkyl group, a substituted or unsubstitutedaryl group, and a substituted or unsubstituted heterocyclic group and ofthese, more preferably the hydrogen atom, the substituted alkyl group,the substituted aryl group, and the substituted heterocyclic group.However, it is unpreferable that R1 and R2 are hydrogen atoms at thesame time. A substituent group containing an asymmetric carbon therein(used as a racemic body) is preferred for the reason of heightening thesolubility of dye and the stability of ink. Furthermore, it ispreferable that a substituent group contains therein a hydroxyl group,an ether group, an ester group, a cyano group, an amido group, or asulfonamido group for the reason of heightening the associating propertyand improving the fastness.

Y₁₁ to Y₁₈ each independently are preferably a hydrogen atom, a halogenatom, an alkyl group, an aryl group, a cyano group, an alkoxy group, anamido group, an ureido group, a sulfonamido group, a carbamoyl group, asulfamoyl group, an alkoxycarbonyl group, a carboxyl group, and a sulfogroup, particularly preferably the hydrogen atom, the halogen atom, thecyano group, the carboxyl group, and the sulfo group, and mostpreferably the hydrogen atom.

a₁₁ to a₁₄ each independently are preferably one or two and particularlypreferably all of them represent one.

M₁ represents a hydrogen atom, a metallic element, or a oxide, ahydroxide, or a halide thereof, particularly preferably Cu, Ni, Zn orAl, and of these, most preferably Cu.

When the phthalocyanine dyes represented by the above-described generalformula (II) are water-soluble, it is preferable that the dyes have anionic hydrophilic group. The ionic hydrophilic group includes a sulfogroup, a carboxyl group, a phosphono group, a quaternary ammonium group,and the like. Of the above-described ionic hydrophilic groups, thecarboxyl group, the phosphono group, and the sulfo group are preferred,and particularly the carboxyl group and the sulfo group are preferred.The carboxyl group, the phosphono group, and the sulfo group may be inthe form of salt, and examples of counter ions forming the salt includean ammonium ion, an alkali metal ion (e.g., lithium ion, sodium ion, andpotassium ion), and an organic cation (e.g., tetramethylammonium ion,tetramethylguanidium ion, and tetramethylphosphonium ion). Of thecounter ions, the alkali metal salt is preferred, and the lithium saltis particularly preferred because of heightening the solubility of dyeand improving the stability of ink.

It is preferable that the number of ionic hydrophilic groups is at leasttwo per molecule of the phthalocyanine dye and it is particularlypreferable to contain at least two sulfo groups and/or carboxyl groups.

About combinations of preferred substituent groups on the compoundsrepresented by the above-described general formula (II), a compound inwhich at least one of various substituent groups is one of theabove-described preferred groups is preferred, a compound in which moreof various substituent groups are the above-described preferred groupsis more preferred, and a compound in which all of substituent groups arethe above-described preferable groups is most preferred.

As chemical structures of the phthalocyanine dyes of this invention, itis preferable that at least one electron-withdrawing group such assulfinyl group, sulfonyl group, and sulfamoyl group is introduced to therespective four benzene rings contained in the phthalocyanine so thatσ_(p) values of the substituent groups contained in the wholephthalocyanine skeleton become 1.6 or more in total.

The Hammett's substituent constant σ_(p) value will be illustrated alittle. The Hammett's rule is an empirical rule proposed by L. P.Hammett in 1935 in order to discuss quantitatively the effect ofsubstituent groups on reactions or equilibrium of benzene derivatives,and the appropriateness thereof is extensively admitted now. Forsubstituent constants searched for the Hammett's rule, there are a σ_(p)value and a σ_(m) value, and these values can be seen in many monographsand, for example, described in detail in “Lange's Handbook ofChemistry”, 12th edition, edited by J. A. Dean, 1979 (Mc Graw-Hill) and“Kagaku-no-ryoiki” Special Number 122, pages 96 to 103, 1979 (Nankodo).

A phthalocyanine derivative represented by the above-described generalformula (I) in general is a mixture of analogous compounds in whichsubstituent groups X_(n) (n=1 to 4) and Y_(m) (m=1 to 4) are differentinevitably in position introduced and number introduced depending uponthe processes of synthesis and accordingly, a general formula representsstatistically and averagely a mixture of analogous compounds in manycases. In this invention, when the mixtures of analogous compounds aredivided into three groups as shown below, some particular mixtures havebeen found to be particularly preferred. That is, the analogous mixturesof phthalocyanine dyes represented by the above-described generalformulas (I) and (II) are classified into the following three groups onthe bases of the positions of substitution and defined. The positions ofY₁₁, Y₁₂, Y₁₃, Y₁₄, Y₁₅, Y₁₆, Y₁₇, and Y₁₈ in formula (II) are taken as1-, 4-, 5-, 8-, 9-, 12-, 13-, and 16-positions, respectively.

(1) β-position substitution type: phthalocyanine dyes having particularsubstituent groups in 2- and/or 3-positions, 6-and/or 7-positions, 10-and/or 11-positions, and 14- and 15-positions.

(2) α-position substitution type: phthalocyanine dyes having particularsubstituent groups in 1- and/or 4-positions, 5- and/or 8-positions, 9-and/or 12-positions, and 13- and/or 16-positions.

(3) α and β-position-mixed substitution type: phthalocyanine dyes havingparticular substituent groups irregularly in 1- to 16-positions.

When derivatives of the phthalocyanine dye different in structure(particularly, different in the position of substitution) are describedin the present description, the terms β-position substitution type,α-position substitution type, and α and β-position-mixed substitutiontype are used as described above.

The phthalocyanine derivatives used in this invention can be synthesizedby methods described or cited in Shirai and Kobayashi,“Futalocianin-Kagaku-to-Kino-”, pages 1 to 62, published by IPC Co., C.C. Leznoff and A. B. P. Lever, “Phthalocyanines—Properties andApplications”, pages 1 to 54, published by VCH, and the like, and bycombinations with methods analogous thereto.

The phthalocyanine compounds represented by general formula (I) of thisinvention can be synthesized, for example, through sulfonation,sulfochlorination, or amidation of an unsubstituted phthalocyaninecompound as described in PCT International Publication Nos. WO00/17275,WO00/08103, WO00/08101, and WO98/41853, JP-A-10-36471, and the like. Inthis case, the sulfonation can occur in all positions of phthalocyaninenucleus and in addition, the number of the sulfonation undergone also isdifficult to control. Accordingly, in the case where sulfo groups areintroduced under these reaction conditions, the position and the numberof sulfo groups introduced into a product can not be identified, and amixture of compounds different in number of substituent groups and inposition of substitution is inevitably produced. When the compound ofthis invention is synthesized from it as a starting material, the numberand the position of substitution of heterocycle-substituted sulfamoylgroup can not be identified and accordingly, the compound of thisinvention is obtained as an α and β-position-mixed substitution typemixture containing some compounds different in number of substituentgroups or in position of substitution.

As described above, for example, the introduction of a number ofelectron-withdrawing groups such as sulfamoyl group into thephthalocyanine nucleus heightens the oxidation potential to increase theozone resistance. According to the above-described method of synthesis,phthalocyanine dyes in which the number of electron-withdrawing groupsintroduced is few, that is, the oxidation potential is negative areinevitably mixed. Accordingly, in order to improve the ozone resistance,the adoption of a method of synthesis where the formation of compoundshaving negative oxidation potentials is inhibited is more preferred.

It is possible to derive the phthalocyanine compounds represented bygeneral formula (II) of this invention, for example, from reaction of aphthalonitrile derivative (compound P) and/or a diiminoisoindolinederivative (compound Q) represented by the following formulas with ametallic derivative represented by general formula (III) or from atetrasulfophthalocyanine compound obtained by reaction of a4-sulfophthalonitrile derivative (compound R) represented by thefollowing formula with a metallic derivative represented by generalformula (III).

In the above-described respective formulas, X_(p) corresponds to X₁₁,X₁₂, X₁₃, or X₁₄ in the above-described general formula (II).Furthermore, Y_(q) and Y_(q′) correspond to Y₁₁, Y₁₂, Y₁₃, Y₁₄, Y₁₅,Y₁₆, Y₁₇, or Y₁₈ in the above-described general formula (II),respectively. In compound R, M′ represents a cation.

The cation that M′ represents is an alkali metal ion such as Li, Na, andK or an organic cation such as triethylammonium ion and pyridinium ion.M-(Y)_(d)  General formula (III)

In general formula (III), M has the same meaning as M in generalformulas (I) and (II), Y represents a monovalent or divalent ligand suchas halogen atom, acetate anion, acetylacetnate, or oxygen, and d is aninteger of one to four.

That is, according to the above-described method of synthesis, desiredsubstituent groups can be introduced by a specific number. When theintroduction of a number of electron-withdrawing groups is desired toraise the oxidation potential, the method of synthesis as describedabove is extremely superior to the method as described already forsynthesizing the phthalocyanine compounds of general formula (I).

The phthalocyanine compounds represented by the above-described generalformula (II) thus obtained are usually mixtures of compounds representedby the following general formulas (a)-1 to (a)-4 that are isomers as tothe respective positions of substitution of X_(p), that is, to form theβ-position substitution type.

In the above-described method of synthesis, use of the very samesubstituent group as X_(p) can lead to synthesis of a phthalocyanine dyeof β-position substitution type where X₁₁, X₁₂, X₁₃, and X₁₄ are thevery same substituent group. On the other hand, use of combinations ofdifferent substituent groups as X_(p) enables synthesis of a dye havingsubstituent groups of the same kind but substituent groups partlydifferent from one another or a dye having substituent groups ofdifferent kinds from one another. Of the dyes of general formula (II),these dyes having electron-withdrawing substituent groups different fromone another are particularly preferred because the solubility andassociating property of dye and the keeping stability of ink can beadjusted.

In this invention, it has been found that the oxidation potential morepositive than 1.0 V (vs SCE) is very important to improvement infastness in all substitution types, and significance of this effect hasnever been foreseen from the above-described background art.Furthermore, the β-position substitution type showed a tendency to beapparently excellent in color hue, light resistance, ozone gasresistance, and the like as compared with the α and β-position-mixedsubstitution type, though details of the cause are unknown.

Specific examples of the phthalocyanine dye represented by theabove-described general formulas (I) and (II) (exemplified compounds I-1to I-12 and 101 to 190) are shown below, but the phthalocyanine dyesused in this invention are not to be construed as limited to thefollowing examples.

Exemplified Compounds

In the table, specific examples of the respective groups (X1, X2), (Y11,Y12), (Y13, Y14), (Y15, Y16), and (Y17, Y18) each independently are outof order: No. M X1 X2 Y11, Y12 Y13, Y14 Y15, Y16 Y17, Y18 101 Cu—SO₂—NH—CH₂—CH₂—SO₃Li —H —H, —H —H, —H —H, —H —H, —H 102 Cu

—H —Cl, —H —Cl, —H —Cl, —H —Cl, —H 103 Cu

—H —H, —H —H, —H —H, —H —H, —H 104 Cu

—H —H, —H —H, —H —H, —H —H, —H 105 Ni

—H —Cl, —H —Cl, —H —Cl, —H —Cl, —H 106 Cu—SO₂—NH—CH₂—CH₂—SO₂—NH—CH₂—COONa —CN —H, —H —H, —H —H, —H —H, —H 107 Cu

—H —H, —H —H, —H —H, —H —H, —H 108 Cu —SO₂—CH₂—CH₂—CH₂—SO₃Li —H —H, —H—H, —H —H, —H —H, —H 109 Cu —SO₂—CH₂—CH₂—CH₂—SO₃K —H —H, —H —H, —H —H,—H —H, —H 110 Cu —SO₂—(CH₂)₅—CO₂K —H —H, —H —H, —H —H, —H —H, —H

In the table, specific examples of the respective groups (X1, X2), (Y11,Y12), (Y13, Y14), (Y15, Y16), and (Y17, Y18) each independently are outof order. No. M X1 X2 Y11, Y12 Y13, Y14 Y15, Y16 Y17, Y18 111 Cu

—H —H, —H —H, —H —H, —H —H, —H 112 Cu

—SO₃Li —H, —H —H, —H —H, —H —H, —H 113 Cu

—H —H, —H —H, —H —H, —H —H, —H 114 Cu

—SO₃Li —H, —H —H, —H —H, —H —H, —H 115 Cu

—H —H, —H —H, —H —H, —H —H, —H 116 Cu

—H —H, —H —H, —H —H, —H —H, —H 117 Cu

—H —H, —H —H, —H —H, —H —H, —H

In the table, specific examples of the respective groups (X1, X2), (Y11,Y12), (Y13, Y14), (Y15, Y16), and (Y17, Y18) each independently are outof order. No. M X1 X2 Y11, Y12 Y13, Y14 Y15, Y16 Y17, Y18 118 Cu

—H —H, —H —H, —H —H, —H —H, —H 119 Cu

—H —H, —H —H, —H —H, —H —H, —H 120 Cu

—H —H, —H —H, —H —H, —H —H, —H 121 Cu

—H —H, —H —H, —H —H, —H —H, —H 122 Cu

—H —H, —H —H, —H —H, —H —H, —H 123 Cu —SO₂NH—C₈H₁₇(t) —H —H, —H —H, —H—H, —H —H, —H 124 Cu

—H —H, —H —H, —H —H, —H —H, —H

In the table, specific examples of the respective groups (X1, X2), (Y11,Y12), (Y13, Y14), (Y15, Y16) and (Y17, Y18) each independently are outof order. No. M X1 X2 Y11, Y12 Y13, Y14 Y15, Y16 Y17, Y18 125 Cu

—H —H, —H —H, —H —H, —H —H, —H 126 Cu

—H —H, —H —H, —H —H, —H —H, —H 127 Cu

—H —H, —H —H, —H —H, —H —H, —H 128 Zn

—CN —H, —H —H, —H —H, —H —H, —H 129 Cu

—H —Cl, —H —Cl, —H —Cl, —H —Cl, —H 130 Cu

—H —H, —H —H, —H —H, —H —H, —H 131 Cu

—H —H, —H —H, —H —H, —H —H, —H

In the table, specific examples of the respective groups (X1, X2), (Y11,Y12), (Y13, Y14), (Y15, Y16), and (Y17, Y18) each independently are outof order. No. M X1 X2 Y11, Y12 Y13, Y14 Y15, Y16 Y17, Y18 132 Cu

—H —H, —H —H, —H —H, —H —H, —H 133 Cu

—H —H, —H —H, —H —H, —H —H, —H 134 Cu

—H —H, —H —H, —H —H, —H —H, —H 135 Cu

—H —H, —H —H, —H —H, —H —H, —H 136 Cu

—H —H, —H —H, —H —H, —H —H, —H

In the table, specific examples of the respective groups (X1, X2), (Y11,Y12), (Y13, Y14), (Y15, Y16), and (Y17, Y18) each independently are outof order. No. M X1 X2 Y11, Y12 Y13, Y14 Y15, Y16 Y17, Y18 137 Cu

—H —H, —H —H, —H —H, —H —H, —H 138 Cu

—H —H, —H —H, —H —H, —H —H, —H 139 Cu

—Cl —H, —H —H, —H —H, —H —H, —H 140 Cu

—H —H, —H —H, —H —H, —H —H, —H

In the table, specific examples of the respective groups (X1, X2), (Y11,Y12), (Y13, Y14), (Y15, Y16), and (Y17, Y18) each independently are outof order Y11, Y13, No. M X1 X2 Y12 Y14 Y15, Y16 Y17, Y18 141 Cu

—H —H, —H —H, —H —H, —H —H, —H 142 Cu

—H —H, —H —H, —H —H, —H —H, —H 143 Cu

—H —H, —H —H, —H —H, —H —H, —H 144 Cu

—H —H, —H —H, —H —H, —H —H, —H 145 Cu —SO₂CH₂CH₂OCH₂CH₂OCH₂CH₂SO₃Li —H—H, —H —H, —H —H, —H —H, —H

M—Pc(Xp₁)_(m)(Xp₂)_(n) In the table, introduction positions of therespective substituent groups (X_(p1)) and X_(p2)) in β-positionsubstituent group type are out of order. No. M Xp₁ m Xp₂ n 146 Cu

3

1 147 Cu —SO₂—NH—CH₂—CH₂SO₃Li 3

1 148 Cu

3 —SO₂NH—CH₂—CH₂—CH₂—SO₂—NH—CH₂—CH₂—O—CH₂—CH₂—OH 1 149 Cu

2

2 150 Cu —SO₂—NH—CH₂—CH₂—SO₂—NH—CH₂CH₂—COONa 3

1 151 Cu

3 —SO₂NH—CH₂—CH₂—O—CH₂—CH₂—OH 1 152 Cu

2.5 —SO₂—CH₂—CH₂—O—CH₂—CH₂—OH 1.5 153 Cu

2

2 154 Cu —SO₂—CH₂—CH₂—CH₂—SO₃Li 3

1 155 Cu —SO₂—CH₂—CH₂—CH₂—COOK 2

2 156 Cu —SO₂—CH₂—CH₂—CH₂—SO₃Li 3

1 157 Cu —SO₂—CH₂—CH₂—O—CH₂—CH₂—SO₃Li 2

2

M—Pc(Xp₁)_(m)(Xp₂)_(n) In the table, introduction positions of therespective substituent groups (X_(p1)) and (X_(p2)) in β-positionsubstituent group type are out of order. No. M Xp₁ m Xp₂ n 158 Cu

3

1 159 Cu —SO₂NHCH₂CH₂—SO₃Li 3

1 160 Cu —SO₂—CH₂—CH₂—O—CH₂—CH₂—O—CH₂—CH₂—SO₃Na 3

1 161 Cu —SO₂CH₂CH₂CH₂SO₃Li 3

1 162 Cu —SO₂CH₂CH₂CH₂SO₃Li 2 —SO₂CH₂CH₂OCH₂CH₂OCH₂CH₂OH 2 163 Cu—SO₂CH₂CH₂CH₂SO₃K 3

1 164 Cu —SO₂CH₂CH₂CH₂SO₃Li 2 —SO₂CH₂CH₂CH₂SO₂N(CH₂CH₂OH)₂ 2 165 Cu—CO—NH—CH₂—CH₂—SO₃K 3 —CO—NH—CH₂—CH₂—O—CH₂—CH₂—OH 1 166 Cu—CO—NH—CH₂—CH₂—SO₂—NH—CH₂—CH₂—COONa 3

1 167 Cu

2.5

1.5 168 Cu

2

2 169 Cu —CO₂—CH₂—CH₂—CH₂—SO₃Li 3

1 170 Cu —CO₂—CH₂—CH₂—CH₂COOK 2

2

M—Pc(Xp₁)_(m)(Xp₂)_(n) In the table, introduction positions of therespective substituent groups (X_(p1)) and (X_(p2)) in β-positionsubstituent group type are out of order. No. M Xp₁ m Xp₂ n 171 Cu—CO₂—CH₂—CH₂—O—CH₂—CH₂—O—CH₂—CH₂—SO₃Na 3

1 172 Cu —SO₂CH₂CH₂OCH₂CH₂O—CH₂CH₂SO₃K 2

2 173 Cu

2

2 174 Cu

3

1 175 Cu —SO₂(CH₂)₃SO₂NH(CH₂)₃N(CH₂CH₂OH)₂ 2

2 176 Cu

3

1 177 Cu —SO₂—CH₂—CH₂—O—CH₂—CH₂—O—CH₃ 2

1 178 Cu —SO₂—CH₂—CH₂—O—CH₂—CH₂—O—CH₂—CH₂—OH 3

1 179 Cu

2

2 180 Cu

3 —SO₂NH—CH₂—CH₂—SO₂NH—CH₂—CH₂—O—CH₂—CH₂—OH 1 181 Cu

3

1 182 Cu

2.5

1.5

M—Pc(Xp₁)_(m)(Xp₂)_(n) In the table, introduction positions of therespective substituent groups (X_(p1)) and (X_(p2)) in β-positionsubstituent group type are out of order. No. M Xp₁ m Xp₂ n 183 Cu

2 —SO₂—CH₂—CH₂—CH₂—SO₂—NH—(CH₂)₃—CH₂—O—CH₂CH₂—OH 2 184 Cu

3 —SO₂—CH₂—CH₂—O—CH₂—CH₂—O—CH₃ 1 185 Cu

3 —SO₂—CH₂—CH₂—O—CH₂—CH₂—O—CH₂—CH₂—O—CH₃ 1 186 Cu

3 —SO₂—CH₂—CH₂—O—CH₂—CH₂—O—CH₂—CH₂—OH 1 187 Cu

3

1 188 Cu

3 —CO₂—CH₂—CH₂—O—CH₂—CH₂—O—CH₃ 1 189 Cu

3

1 190 Cu

3 —CO—NH—CH₂—CH₂—O—CH₂—CH₂—O—CH₃ 1

The structure of the phthalocyanine compounds of compound Nos. 146 to190 represented by M-Pc(X_(p1))_(m)(X_(p2))_(n) is as follows

The phthalocyanine dyes represented by the above-described generalformula (I) can be synthesized according to the above-described patents.Furthermore, the phthalocyanine dyes represented by general formula (II)can be synthesized according to methods described in the respectivedescriptions of JP-A-2001-226275, JP-A-2001-96610, JP-A-2001-47013, andJP-A-2001-193638 in addition to the methods of synthesis as describedabove. Furthermore, starting materials, dye intermediates, and processesof synthesis are not limited to these.

[Ink]

The ink for ink jet recording of this invention (The ink also is calledthe ink of this invention) is prepared by dissolving or dispersing atleast one of the above-described azo dyes or phthalocyanine dyes in anaqueous medium and is a magenta ink or a cyan ink containing the azo dyeor phthalocyanine dye preferably in an amount of 0.2 to 20 mass percentand more preferably 0.5 to 15 mass percent.

In addition of the above-described particular azo dyes or phthalocyaninedyes relating to this invention, other dyes also can be added theretofor the purpose of adjusting color tones. Furthermore, in order tocompose an ink set for full colors, a yellow ink and a black ink areused together with the inks of this invention, and the respectivedyestuffs are used for the inks. Moreover, other magenta inks and cyaninks than those of this invention also can be used. Examples of thedyestuffs usable jointly include the following dyestuffs.

The yellow dyestuffs include, for example, aryl or heteryl azo dyestuffshaving as coupling components phenols, naphthols, anilines, pyrazolones,pyridones, or open-chain type active methylene compounds; for example,azo methine dyestuffs having open-chain type active methylene compoundsas coupling components; for example, methine dyestuffs such asbenzylidene dyestuff or monomethineoxonol dyestuff; and for example,quinone-series dyestuffs such as naphthoquinone dyestuff oranthraquinone dyestuff; and as other dyestuff species, quinophthalonedyestuffs, nitro and nitroso dyestuffs, acrydine dyestuffs, acrydinonedyestuffs, and the like. These dyestuffs may be those assuming a yellowcolor for the first time by dissociating a part of the chromophore andin this case, the counter cations may be inorganic cations such asalkali metal ion or ammonium ion, organic cations such as pyridinium ionor quaternary ammonium ion, or moreover, polymer cations containingthese cations in partial structures.

The magenta dyestuffs include, for example, aryl or heteryl azodyestuffs having phenols, naphthols, or anilines as coupling components;for example, azo methine dyestuffs having pyrazolones orpyrazolotriazoles as coupling components; for example, methine dyestuffssuch as arylidene dyestuff, styryl dyestuff, merocyanine dyestuff, oroxonol dyestuff; carbonium dyestuffs such as diphenylmethane dyestuff,triphenylmethane dyestuff, or xanthene dyestuff, for example, quinonedyestuffs such as naphthoquinone, anthraquinone, or anthrapyridone; andfor example, condensed polycyclic dyestuffs such as dioxazine dyestuff.These dyestuffs may be those assuming a magenta color for the first timeby dissociating a part of the chromophore and in this case, the countercations may be inorganic cations such as alkali metal ion or ammoniumion, organic cations such as pyridinium ion or quaternary ammonium ion,or moreover polymer cations containing these cations in partialstructures.

The cyan dyestuffs include, for example, azomethine dyestuffs such asindoaniline dyestuff or indophenol dyestuff; polymethine dyestuffs suchas cyanine dyestuff, oxonol dyestuff, or merocyanine dyestuff; carboniumdyestuffs such as diphenylmethane dyestuff, triphenylmethane dyestuff,or xanthene dyestuff; phthalocyanine dyestuffs; anthraquinone dyestuffs;aryl or heteryl azo dyestuffs having, for example, phenols, naphthols,or anilines as coupling components, and indigo and thioindigo dyestuffs.These dyestuffs may be those assuming a cyan color for the first time bydissociating a part of the chromophore and in this case, the counterions may be inorganic cations such as alkali metal ion or ammonium ion,inorganic cations such as pyridinium ion or quaternary ammonium ion, andmoreover polymer cations containing these cations in partial structures.

Furthermore, black dyestuffs such as polyazo dyestuff also can be used.

Other water-soluble dyes include a direct cotton dye, an acid dye, afood dye, a basic dye, a reactive dye, and the like. Preferred dyesinclude:

-   C.I. Direct Red 2, 4, 9, 23, 26, 31, 39, 62, 63, 72, 75, 76, 79, 80,    81, 83, 84, 89, 92, 95, 111, 173, 184, 207, 211, 212, 214, 218, 21,    223, 224, 225, 226, 227, 232, 233, 240, 241, 242, 243, and 247;-   C.I. Direct violet 7, 9, 47, 48, 51, 66, 90, 93, 94, 95, 98, 100,    and 101;-   C.I. Direct Yellow 8, 9, 11, 12, 27, 28, 29, 33, 35, 39, 41, 44, 50,    53, 58, 59, 68, 86, 87, 93, 95, 96, 98, 100, 106, 108, 109, 110,    130, 132, 142, 144, 161, and 163;-   C.I. Direct Blue 1, 10, 15, 22, 25, 55, 67, 68, 71, 76, 77, 78, 80,    84, 86, 87, 90, 98, 106, 108, 109, 151, 156, 158, 159, 160, 168,    189, 192, 193, 194, 199, 200, 201, 202, 203, 207, 211, 213, 214,    218, 225, 229, 236, 237, 244, 248, 249, 251, 252, 264, 270, 280, 288    289, and 291;-   C.I. Direct Black 9, 17, 19, 22, 32, 51, 56, 62, 69, 77, 80, 91, 94,    97, 108, 112, 113, 114, 117, 118, 121, 122, 125, 132, 146, 154, 166,    168, 173, and 199;-   C.I. Acid Red 35, 42, 52, 57, 62, 80, 82, 111, 114, 118, 119, 127,    128, 131, 143, 151, 154, 158, 249, 254, 257, 261, 263, 266, 289,    299, 301, 305, 336, 337, 361, 396, and 397;-   C.I. Acid Violet 5, 34, 43, 47, 48, 90, 103, and 126;-   C.I. Acid Yellow 17, 19, 23, 25, 39, 40, 42, 44, 49, 50, 61, 64, 76,    79, 110, 127, 135, 143, 151, 159, 169, 174, 190, 195, 196, 197, 199,    218, 219, 222, and 227;-   C.I. Acid Blue 9, 25, 40, 41, 62, 72, 76, 78, 80, 82, 92, 106, 112,    113, 120, 127:1, 129, 138, 143, 175, 181, 205, 207, 220, 221, 230,    232, 247, 258, 260, 271, 277, 278, 279, 280, 288, 290, and 326;-   C.I. Acid Black 7, 24, 29, 48, 52:1, and 172;-   C.I. Reactive Red 3, 13, 17, 19, 21, 22, 23, 24, 29, 35, 37, 40, 41,    43, 45, 49, and 55;-   C.I. Reactive Violet 1, 3, 4, 5, 6, 7, 8, 9, 16, 17, 22, 23, 24, 26,    27, 33, and 34;-   C.I. Reactive Yellow 2, 3, 13, 14, 15, 17, 18, 23, 24, 25, 26, 27,    29, 35, 37, 41, and 42;-   C.I. Reactive Blue 2, 3, 5, 8, 10, 13, 14, 15, 17, 18, 19, 21, 25,    26, 27, 28, 29, and 38;-   C.I. Reactive Black 4, 5, 8, 14, 21, 23, 26, 31, 32, and 34;-   C.I. Basic Red 12, 13, 14, 15, 18, 22, 23, 24, 25, 27, 29, 35, 36,    38, 39, 45, and 46;-   C.I. Basic Violet 1, 2, 3, 7, 10, 15, 16, 20, 21, 25, 27, 28, 35,    37, 39, 40, and 48;-   C.I. Basic Yellow 1, 2, 4, 11, 13, 14, 15, 19, 21, 23, 24, 25, 28,    29, 32, 36, 39, and 40;-   C.I. Basic Blue 1, 3, 5, 7, 9, 22, 26, 41, 45, 46, 47, 54, 57, 60,    62, 65, 66, 69, and 71; and-   C.I. Basic Black 8, and the like.

The dyestuffs including the azo dyes or the phthalocyanine dyes used inthis invention are substantially water-soluble or water-dispersible.Specifically, the water solubility of the dyestuffs including therespective dyes is preferably 2 mass percent or more and more preferably5 mass percent or more at 20° C.

Furthermore, pigment also can be simultaneously used for the inks ofthis invention and other inks used in combination with these inks for anink set.

Pigments used in this invention include pigments on the market andfurther known pigments described in various literatures. As theliteratures, there are “Color Index” (edited by The Society of Dyers andColourists), “Kaiteishinpan Ganryo Binran” (edited by Nippon GanryoGijutsu kyokai, 1989), “Saishin Ganryo Oyo Gijutsu” (published by CMCShuppan, 1986), “Insatsu Inki Gijutsu” (edited by CMC Shuppan, 1984), W.Herbst and K. Hunger, “Industrial Organic Pigments” (VCHVerlagsgesellschaft, 1993), and the like. Specifically, the pigmentsinclude, as organic pigments, azo pigments (azo lake pigment, insolubleazo pigment, condensed azo pigment, and chelated azo pigment),polycyclic pigments (phthalocyanine pigment, anthraquinone pigment,perylene and perynone pigment, indigo pigment, quinacridone pigment,dioxazine pigment, isoindolinone pigment, quinophthalone pigment,diketopyrrolopyrrole pigment, etc.), in-mold decorating lake pigments(lake pigment of acid or basic dye), azine pigments, and the like, andas inorganic pigments, C.I. Pigment Yellow 34, 37, 42, 53, etc. asyellow pigments, C.I. Pigment Red 101, 108, etc. as red pigments, C.I.Pigment Blue 27, 29, 17:1, etc. as blue pigments, C.I. Pigment Black 7,magnetite, etc. as black pigments, and C.I. Pigment White 4, 6, 18, 21,etc. as white pigments.

Pigments having color tones desirable for image formation includepreferably, as blue or cyan pigments, phthalocyanine pigments,anthraquinone-series indanthrone pigments (e.g., C.I. Pigment Blue 60,etc.), and in-mold decorating lake pigment-series triarylcarboniumpigments and particularly, most preferably the phthalocyanine pigments(as preferable examples, copper phthalocyanine such as C.I. Pigment Blue15:1, 15:2, 15:3, 15:4, 15:6, monochloro or lowly chlorinated copperphthalocyanine, pigments described in European Patent No. 860,475 asaluminum phthalocyanine, non-metallic phthalocyanine of C.I. PigmentBlue 16, phthalocyanines containing Zn, Ni, or Ti as central metal, andof these, C.I. Pigment Blue 15:3 and 15:4, and the aluminumphthalocyanine) are most preferred.

Red or violet pigments used preferably are azo pigments (as preferredexamples, C.I. Pigment Red 3, 5, 11, 22, 38, 48:1, 48:2, 48:3, 48:4,49:1, 52:1, 53:1, 57:1, 63:2, 144, 146, 184, etc. and of these,preferably C.I. Pigment Red 57:1, 146, and 184), quinacridone pigments(as preferred examples, C.I. Pigment Red 122, 192, 202, 207, and 209,C.I. Pigment Violet 19 and 42 and of these, preferably C.I. Pigment Red122), in-mold decorating lake pigment-series triarylcarbonium pigments(as preferred examples, xanthene-series C.I. Pigment Red 81:1 and C.I.Pigment Violet 1, 2, 3, 27, and 39), dioxazine-series pigments (forexample, C.I. Pigment Violet 23 and 37), diketopyrrolopyrrole pigments(for example, C.I. Pigment Red 254), perylene pigments (for example,C.I. Pigment Violet 29), anthraquinone pigments (for example, C.I.Pigment Violet 5:1, 31, and 33), and thioindigo-series pigments (forexample, C.I. Pigment Red 38 and 88).

Yellow pigments used preferably are azo pigments (as preferred examples,monoazo pigment-series C.I. Pigment Yellow 1, 3, 74, and 98, disazopigment-series C.I. Pigment Yellow 12, 13, 14, 16, 17, and 83, combinedazo-series C.I. Pigment Yellow 93, 94, 95, 128, and 155,benzimidazolone-series C.I. Pigment Yellow 120, 151, 154, 156, 180, etc.and of these, preferably those prepared from benzidine-series compoundsas starting materials), isoindoline and isoindolinone-series pigments(as preferred examples, C.I. Pigment Yellow 109, 110, 137, 139, etc.),quinophthalone pigments (as preferred examples, C.I. Pigment Yellow 138,etc.), and flavanthrone pigments (for example, C.I. Pigment Yellow 24,etc.).

Preferred black pigments include inorganic pigments (as preferredexamples, carbon black and magnetite) and aniline black.

Furthermore, orange pigments (C.I. Pigment Orange 13, 16, etc.) or greenpigments (C.I. Pigment Green 7, etc.) also can be used.

The pigments used in this technique may be the aforesaid bare pigmentsor may be pigments having undergone a surface treatment. Methods of thesurface treatment include a method of coating surface with a resin or awax, a method of allowing a surfactant to adhere, and a method ofallowing a reactive substance (e.g., silane coupling agents, epoxycompounds, radicals generated from polyisocyanate or diazonium salt,etc.) to bond to the surface of pigment, which are described in thefollowing literatures.

-   -   (1) Kinzokusekken-no-seisitsu to Oyo (Saiwai Shobo)    -   (2) Insatsu-inki Insatsu (CMC Shuppan, 1984)    -   (3) Saishin Ganryo Oyo Gijutsu (CMC Shuppan, 1986)    -   (4) U.S. Pat. Nos. 5,554,739 and 5,571,311    -   (5) JP-A-9-151342, JP-A-10-140065, JP-A-10-292143, and        JP-A-11-166145

Particularly, self-dispersible pigments prepared by acting diazoniumsalts on carbon black as described in the US patents of the above (4)and encapsulated pigments prepared according to methods of the JapanesePatents of the above (5) are particularly effective because dispersionstability is obtained without using an excess dispersant in ink.

In this invention, the pigments can be further dispersed by use of adispersant. Various known dispersants, for example, low moleculardispersants of surfactant type or high molecule-type dispersants, can beused according to pigments used. Examples of the dispersants includethose described in JP-A-3-69949, European Patent No. 549,486, and thelike. When a dispersant is used, a pigment derivative called a synergistmay be added to promote the adsorption of the dispersant on pigment.

The particle size of pigments usable in this invention is preferably inthe range of from 0.01 to 10 μm and further preferably from 0.05 to 1 μmafter dispersion.

Known techniques for dispersion used in the preparation of ink or thepreparation of toner can be used as methods for dispersing the pigment.Dispersing machines includes a vertical or horizontal agitator mill, anattritor, a colloid mill, a ball mill, a triple roll mill, a pearl mill,a super mill, an impeller, a disperser, a KD mill, a dynatron, apressure kneader, and the like. Details are described in “Saishin GanryoOyo Gijutsu” (CMC Shuppan, 1986).

The ink of this invention is further characterized by containing atleast one selected from compounds represented by the following generalformula (A) and compounds represented by the following general formula(B).

In the formula, X represents a group containing carbonyl or aheteroatom. Z₁ represents a group of atoms that can form a cyclicorganic substance.

General Formula (B)X¹—Y-Z

In the formula, X¹ represents a group shown by —N(Q₁)-Q₂. Z represents agroup shown by —N(Q₁)-Q₂ or a group shown by —O-Q₃. Y represents a groupshown by —W-(G)_(k)-(H)_(n)—. Herein, W and H represent a group shown by—CO—, —SO₂—, or —PO(Q₄)—. G represents a divalent connecting group. Q₁to Q₄ represent any of a hydrogen atom, an amino group, an alkyl group,an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group,a heteroaryl group, an alkoxy group, an aryloxy group, a heterocyclicoxy group, a heteroaryloxy group, an alkylamino group, an arylaminogroup, a heterocyclic amino group, and a heteroarylamino group. X and Zmay combine with each other to form a ring. k and n represent 0 or 1,respectively.

In general formula (A), X represents a group containing carbonyl or aheteroatom.

Examples of X include a carbonyl group, an oxycarbonyl group, a carbonicester group, an amido group, an urethane group, an ureido group, anamino group, an imino group, an ether group, a thioether group, aphosphoric acid derivative group, a phosphonic acid derivative group, asulfonyl group, a sulfonamido group, a sulfonylurea group, and the like,and of these, the amido group is preferred.

Z₁ represents a group of atoms that can form a cyclic organic substance.Although Z₁ may be a ring formed solely by carbon atoms, Z₁ may furthercontain a heteroatom in a ring of carbon atoms. The ring may have or maynot have aromaticity. Furthermore, the ring may form a compoundcondensed with a plurality of rings.

The compounds represented by general formula (A) can have varioussubstituent groups in structures. Examples of the substituent groupsinclude an alkyl group (that has preferably a carbon number of one to20, more preferably a carbon number of one to 12, and particularlypreferably a carbon number of one to eight and includes, for example,methyl, ethyl, isopropyl, tert-butyl, n-octyl, n-decyl, n-hexadecyl,cyclopropyl, cyclopentyl, cyclohexyl, etc.), an alkyenyl group (that haspreferably a carbon number of two to 20, more preferably a carbon numberof two to 12, and particularly preferably a carbon number of two toeight and includes, for example, vinyl, allyl, 2-butenyl, 3-pentenyl,etc.), an alkynyl group (that has preferably a carbon number of two to20, more preferably a carbon number of two to 12, and particularlypreferably a carbon number of two to eight and includes, for example,propargyl, 3-pentinyl, etc.), an aryl group (that has preferably acarbon number of six to 30, more preferably a carbon number of six to20, and particularly preferably a carbon number of six to 12 andincludes, for example, phenyl, p-methylphenyl, naphthyl, etc.), an aminogroup (that has preferably a carbon number of zero to 20, morepreferably a carbon number of zero to 12, and particularly preferably acarbon number of zero to six and includes, for example, amino,methylamino, dimethylamino, diethylamino, diphenylamino, dibenzylamino,etc.), an alkoxy group (that has preferably a carbon number of one to20, more preferably a carbon number of one to 12, and particularlypreferably a carbon number of one to eight and includes, for example,methoxy, ethoxy, butoxy, etc.), an aryloxy group (that has preferably acarbon number of six to 20, more preferably a carbon number of six to16, and particularly preferably a carbon number of six to 12 andincludes, for example, phenyloxy, 2-naphthyloxy, etc.), an acyl group(that has preferably a carbon number of one to 20, more preferably acarbon number of one to 16, and particularly preferably a carbon numberof one to 12 and includes, for example, acetyl, benzoyl, formyl,pivaloyl, etc.), an alkoxycarbonyl group (that has a carbon number oftwo to 20, more preferably a carbon number of two to 16, andparticularly preferably a carbon number of two to 12 and includes, forexample, methoxycarbonyl, ethoxycarbonyl, etc.), an aryloxycarbonylgroup (that has preferably a carbon number of seven to 20, morepreferably a carbon number of seven to 16, and particularly preferably acarbon number of seven to 10 and includes for example,phenyloxylcarbonyl, etc.), an acyloxy group (that has preferably acarbon number of two to 20, more preferably a carbon number of two to16, and particularly preferably a carbon number of two to 10 andincludes, for example, acetoxy, benzoyloxy, etc.), an acylamino group(that has preferably a carbon number of two to 20, more preferably acarbon number of two to 16, and particularly preferably a carbon numberof two to 10 and includes, for example, acetylamino, benzoylamino,etc.), an alkoxycarbonylamino group (that has preferably a carbon numberof two to 20, more preferably a carbon number of two to 16, andparticularly preferably a carbon number of two to 12 and includes, forexample, methoxycarbonylamino, etc.), an aryloxycarbonylamino group(that has preferably a carbon number of seven to 20, more preferably acarbon number of seven to 16, and particularly preferably a carbonnumber of seven to 12 and includes, for example, phenyloxycarbonylamino,etc.), a sulfonylamino group (that has preferably a carbon number of oneto 20, more preferably a carbon number of one to 16, and particularlypreferably a carbon number of one to 12 and includes, for example,methylsulfonylamino, phenylsulfonylamino, etc.), a sulfamoyl group (thathas preferably a carbon number of zero to 20, more preferably a carbonnumber of zero to 16, and particularly preferably a carbon number ofzero to 12 and includes, for example, sulfamoyl, methylsulfamoyl,dimethylsulfamoyl, phenylsulfamoyl, etc.), a carbamoyl group (that haspreferably a carbon number of one to 20, more preferably a carbon numberof one to 16, and particularly preferably a carbon number of one to 12and includes, for example, carbamoyl, methylcarbamoyl, diethylcarbamoyl,phenylcarbamoyl, etc.), an alkylthio group (that has preferably a carbonnumber of one to 20, more preferably a carbon number of one to 16, andparticularly preferably a carbon number of one to 12 and includes, forexample, methylthio, ethylthio, etc.), an arylthio (that has preferablya carbon number of six to 20, more preferably a carbon number of six to16, and particularly preferably a carbon number of six to 12 andincludes, for example, phenylthio, etc.), a sulfonyl group (that haspreferably a carbon number of one to 20, more preferably a carbon numberof one to 16, and particularly preferably a carbon number of one to 12and includes, for example, mesyl, tosyl, etc.), a sulfinyl group (thathas preferably a carbon number of one to 20, more preferably a carbonnumber of one to 16, and particularly preferably a carbon number of oneto 12 and includes, for example, methylsufinyl, phenylsulfinyl, etc.),an ureido group (that has preferably a carbon number of one to 20, morepreferably a carbon number of one to 16, and particularly preferably acarbon number of one to 12 and includes, for example, ureido,methylureido, phenylureido, etc), a phosphoric amido group (that haspreferably a carbon number of one to 20, more preferably a carbon numberof one to 16, and particularly preferably a carbon number of one to 12and includes, for example, diethyl phosphoric amido, phenyl phosphoricamido, etc.), a hydroxy group, a mercapto group, a halogen atom (e.g.,fluorine atom, chlorine atom, bromine atom, and iodine atom), a cyanogroup, a sulfo group, a carboxyl group, a nitro group, a hydroxamic acidgroup, a sulfino group, a hydrazino group, an imino group, aheterocyclic group (that has preferably a carbon number of one to 30 andmore preferably a carbon number of one to 12 and includes thosecontaining, for example, a nitrogen atom, an oxygen atom, or a sulfuratom as a heteroatom, and specifically, imidazolyl, pyridyl, quinolyl,furyl, thienyl, piperidyl, morpholino, benzoxazolyl, benzimidazolyl,benzothiazolyl, carbazolyl, azepinyl, etc.), and a silyl group (that haspreferably a carbon number of three to 40, more preferably a carbonnumber of three to 30, and particularly preferably a carbon number ofthree to 24 and includes, for example, trimethylsilyl, triphenylsilyl,etc.), and the like. These substituent groups may be furthersubstituted. When there exist two or more substituent groups, thesubstituent groups may be the same or different from each other.Furthermore, if possible, the substituent groups may combine with eachother to form a ring.

The compounds represented by general formula (A) are preferablymonocyclic and preferably liquid under the conditions of ordinarytemperatures and normal pressures. Furthermore, although the variouscompounds of oil-soluble structure or water-soluble structure can beused, water-soluble compounds are preferred.

As shown below, compounds used preferably as the compounds representedby general formula (A) include cyclohexanone, cyclopentanone, ethylenecarbonate, γ-butyrolactone, propylene carbonate, 2-pyrrolidone,ε-caprolactam, tetrahydrofuran, 1,4-dioxane,1,3-dimethylimidazolidinone, N-methylpyrrolidone, ethylene urea,sulfolane, pyridine, pyrazine, morpholine, 1-methyl-2-pyrridone,2-methyl-2-oxazoline, 2-ethyl-2-oxazoline, 2,4,4-trimethyl-2-oxazoline,and the like, but it is a matter of course that this invention is notlimited by these.

The amount of the compounds represented by general formula (A) can beused in a wide range, preferably from 0.001 to 50 mass percent andparticularly preferably from 0.1 to 10 mass percent of ink.

Subsequently, the compounds represented by general formula (B) areillustrated.X¹—Y-Z

In the compounds represented by general formula (B), X¹ represents agroup shown by —N(Q₁)-Q₂. Z represents a group shown by —N(Q₁)-Q₂ or agroup shown by —O-Q₃. Y represents a group shown by —W-(G)_(k)-(H)_(n)—.

Herein, W and H represent —CO—, —SO₂—, and —PO(Q₄)- and preferably thecarbonyl group or the sulfonyl group.

G represents a divalent connecting group. The divalent connecting grouppreferably includes an alkylene group, an alkenylene group, analkynylene group, an arylene group, an ether group, an imino group, analkylimino group, a thioether group, a group represented by -V- (Vrepresents a heterocycle), and the like.

The alkylene group that G represents has preferably a carbon number ofone to 20 and include, for example, a methylene group, an ethylenegroup, a 1,3-propylene group, a 1,2-propylene group, a 1,4-butylenegroup, a 1,6-hexylene group, a 1,8-octylene group, and the like.

The alkenylene group has preferably a carbon number of one to 20 andincludes, for example, a vinylene group and the like.

The arylene group has preferably a carbon number of one to 20 andinclude, for example, a 1,2-phenylene group, a 1,3-phenylene group, a1,4-phenylene group, a 1,8-naphthylene group, a 1,5-naphthylene group, a2,6-naphthylene group, and the like.

The ether group, the imino group, the alkylimino group, the thioethergroup, the group represented by -V- (V represents a heterocycle), andthe like are included.

Q₁ to Q₄ represent any of a hydrogen atom, an amino group, an alkylgroup, an alkenyl group, an alkynyl group, an aryl group, a heterocyclicgroup, a heteroaryl group, an alkoxy group, an aryloxy group, aheterocyclic oxy group, a heteroaryloxy group, an alkylamino group, anarylamino group, a heterocyclic amino group, and a heteroarylaminogroup.

The alkyl group that Q₁ to Q₄ represent has preferably a carbon numberof one to 30 and more preferably a carbon number of one to 15 andincludes, for example, a methyl group, a t-butyl group, a cyclohexylgroup, and the like.

The alkenyl group has preferably a carbon number of two to 30 and morepreferably a carbon number of two to 15. Examples of the alkenyl groupinclude a vinyl group, a 1-propenyl group, a 1-buten-2-yl group, acyclohexen-1-yl, and the like.

The alkynyl group has preferably a carbon number of two to 30 and morepreferably a carbon number of two to 15, and examples thereof include anethynyl group, a 1-propynyl group, and the like.

The aryl group has preferably a carbon number of six to 30 and morepreferably a carbon number of six to 15, and examples thereof include aphenyl group, a tolyl group, a xylyl group, a naphthyl group, abiphenylyl group, a pyrenyl group, and the like.

The heterocyclic group and the heteroaryl group are preferably of a fiveor six-membered ring and may be condensed with other rings. Theheteroatom includes, for example, a nitrogen atom, an oxygen atom, and asulfur atom. These groups have preferably a carbon number of two to 30and more preferably a carbon number of two to 15. Examples of thesegroups include a pyridyl group, a piperidyl group, an oxazolyl group, anoxadiazolyl group, a tetrahydrofuryl group, a thienyl group, and thelike.

The alkoxy group has preferably a carbon number of one to 30 and morepreferably a carbon number of one to 15. Examples of the group include amethoxy group, an ethoxy group, a cyclohexyloxy group, and the like.

The aryloxy group has preferably a carbon number of six to 30 and morepreferably a carbon number of six to 15. Examples of the group include aphenoxy group, a 1-naphthoxy group, a 4-phenylphenoxy group, and thelike.

Examples of heterocycles in the heterocyclic oxy group, theheteroaryloxy group, the heterocyclic amino group, and a heteroarylaminogroup are similar to those as described above.

The amino groups in the alkylamino group, the arylamino group, theheterocyclic amino group, and the heteroarylamino group can be either ofprimary and secondary amino groups.

The respective groups of these G and Q₁ to Q₂ can have substituentgroups in the case where substitution is possible, and examples of thesubstituent groups include a halogen atom, a cyano group, a formylgroup, an alkyl group, an alkenyl group, an alkynyl group, an arylgroup, a heterocyclic group, primary to tertiary amino groups, an iminogroup, an alkoxy group, an aryloxy group, an alkylthio group, anarylthio group, a carbonamido group, a sulfonamido group, a carbamoylgroup, a sulfamoyl group, an alkylcarbonyl group, an arylcarbonyl group,an alkylsulfonyl group, an arylsulfonyl group, an alkoxycarbonyl group,an aryloxycarbonyl group, an alkylcarbonyloxy group, an arylcarbonyloxygroup, an urethane group, an ureido group, and a carbonic ester group.Of these, the alkyl group, the aryl group, the alkoxy group, and thearyloxy group are preferred, and the alkyl group and aryl group areparticularly preferred.

When the substituent group is the halogen atom, the halogen atom ispreferably a fluorine atom, a chlorine atom, a bromine atom, and aniodine atom.

When the substituent group is the alkyl group, the alkyl group haspreferably a carbon number of one to 30 and more preferably a carbonnumber of one to 15. Examples of the alkyl group include a methyl group,a t-butyl group, a cyclohexyl group, and the like.

The alkenyl group has preferably a carbon number of two to 30 and morepreferably a carbon number of two to 15, and examples thereof include avinyl group, a 1-propenyl group, a 1-buten-2-yl group, acyclohexen-1-yl, and the like.

The alkynyl group has preferably a carbon number of two to 30 and morepreferably a carbon number of two to 15, and examples thereof include anethynyl group, a 1-propynyl group, and the like.

The aryl group has preferably a carbon number of six to 30 and morepreferably a carbon number of six to 15, and examples thereof include aphenyl group, a tolyl group, a xylyl group, a naphthyl group, abiphenylyl group, a pyrenyl group, and the like.

The heterocyclic group is preferably of a five or six-membered ring andmay be condensed with other rings. The heteroatom includes, for example,a nitrogen atom, an oxygen atom, and a sulfur atom. The heterocyclicgroup has preferably a carbon number of two to 30 and more preferably acarbon number of two to 15, and examples thereof include a pyridylgroup, a piperidyl group, an oxazolyl group, an oxadiazolyl group, atetrahydrofuryl group, a thienyl group, and the like.

The primary to tertiary amino groups include an amino group, analkylamino group, an arylamino group, a dialkylamino group, diarylaminogroup, an alkylarylamino group, a heterocyclic amino group, abisheterocyclic amino group, and the like, a tertiary amino group ispreferred, the amino groups have preferably a carbon number of one to 30and more preferably a carbon number of one to 16, and examples thereofinclude a dimehylamino group, a diphenylamino group, aphenylnaphthylamino group, and the like.

The imino group is a group represented by —CR₁₁═NR₁₂ or —N═CR₁₃R₁₄ andherein, R₁₁ to R₁₄ are hydrogen atoms or groups selected from an alkylgroup, an aryl group, a heterocyclic group, an alkoxy group, an aryloxygroup, and primary to tertiary amino groups. The imino group haspreferably a carbon number of one to 30 and more preferably a carbonnumber of one to 15.

The alkoxy group has preferably a carbon number of one to 30 and morepreferably a carbon number of one to 15, and examples thereof include amethoxy group, an ethoxy group, a cyclohexyloxy group, and the like.

The aryloxy group has preferably a carbon number of six to 30 and morepreferably a carbon number of six to 15, and examples thereof include aphenoxy group, a 1-naphthoxy group, a 4-phenylphenoxy group, and thelike.

The alkylthio group has preferably a carbon number of one to 30 and morepreferably a carbon number of one to 15, and examples thereof include amethythio group, an ethylthio group, a cyclohexylthio group, and thelike.

The arylthio group has preferably a carbon number of six to 30 and morepreferably a carbon number of six to 15, and examples thereof include aphenylthio group, a tolylthio group, and the like.

The carbonamido group has preferably a carbon number of one to 30 andmore preferably a carbon number of one to 15, and examples thereofinclude an acetamido group, a benzoylamido group, anN-methylbenzoylamido group, and the like.

The sulfonamido group has preferably a carbon number of one to 30 andmore preferably a carbon number of one to 15, and examples thereofinclude a methanesulfonamido group, a benzenesulfonamido group,p-toluenesulfonamido group, and the like.

The carbamoyl group has preferably a carbon number of one to 30 and morepreferably a carbon number of one to 15. Examples of the carbamoyl groupinclude an unsubstituted carbamoyl group, a methylcarbamoyl group, adimethylcarbamoyl group, a phenylcarbamoyl group, a diphenylcarbamoylgroup, a dioctylcarbamoyl group, and the like.

The sulfamoyl group has preferably a carbon number of one to 30 and morepreferably a carbon number of one to 15, and examples thereof include anunsubstituted sulfamoyl group, a methylsulfamoyl group, adimethylsulfamoyl group, a phenylsulfamoyl group, a diphenylsulfamoylgroup, a dioctylsulfamoyl group, and the like.

The alkylcarbonyl group has preferably a carbon number of one to 30 andmore preferably a carbon number of one to 15, and examples thereofinclude an acetyl group, a propionyl group, a butyroyl group, a lauroylgroup, and the like.

The arylcarbonyl group has preferably a carbon number of six to 30 andmore preferably a carbon number of six to 15, and examples thereofinclude a benzoyl group, a naphthoyl group, and the like.

The alkylsulfonyl group has preferably a carbon number of one to 30 andmore preferably a carbon number of one to 15, and examples thereofinclude a methanesulfonyl group, an ethanesulfonyl group, and the like.

The arylsulfonyl group has preferably a carbon number of six to 30 andmore preferably a carbon number of six to 15, and examples thereofinclude a benzenesulfonyl group, a p-toluenesulfonyl group, a1-naphthalenesulfonyl group, and the like.

The alkoxycarbonyl group has preferably a carbon number of one to 30 andmore preferably a carbon number of one to 15, and examples thereofinclude a methoxycarbonyl group, an ethoxycarbonyl group, abutoxycarbonyl group, and the like.

The aryloxycarbonyl group has preferably a carbon number of six to 30and more preferably a carbon number of six to 15, and examples thereofinclude a phenoxycarbonyl group, a 1-naphthoxycarbonyl group, and thelike.

The alkylcarbonyloxy group has preferably a carbon number of one to 30and more preferably a carbon number of one to 15, and examples thereofinclude an acetoxy group, a propionyloxy group, a butyroyloxy group, andthe like.

The arylcarbonyloxy group has preferably a carbon number of six to 30and more preferably a carbon number of six to 15, and examples thereofinclude a benzoyloxy group, a 1-naphthoyloxy group, and the like.

The urethane group has preferably a carbon number of one to 30 and morepreferably a carbon number of one to 15, and examples thereof include amethoxycarbonamido group, a phenoxycarbonamido group, amethylaminocarbonamido group, and the like.

The ureido group has preferably a carbon number of one to 30 and morepreferably a carbon number of one to 15, and examples thereof include amethylaminocarbonamido group, a dimethylaminocarbonamido group, adiphenylaminocarbonamido group, and the like.

The carbonic ester group has preferably a carbon number of one to 30 andmore preferably a carbon number of one to 15, and examples thereofinclude a methoxycarbonyloxy group, a phenoxycarbonyloxy group, and thelike.

Of these substituent groups, the alkyl group, the aryl group, the alkoxygroup, and the aryloxy group are preferred and the alkyl group and thearyl group are particularly preferred.

X¹ and Z are preferably hydrogen atoms or amino groups substituted byalkyl groups. X¹ and Z may combine with each other to form a ring. k andn represent zero or one, respectively, and preferably zero.

An amount of the compound represented by general formula (B) may bepreferably used in a wide range, but is preferably from 0.1 to 80 masspercent and more preferably from one to 50 mass percent of ink.

Although specific examples of the compound represented by generalformula (B) are shown below, it is a matter of course that thisinvention is not to be construed as limited by these examples.

(Specific Examples)

-   Urea-   Methylurea-   N,N′-Dimethylurea-   Tetramethylurea-   Ethylurea-   Tetraethylurea-   Ethyleneurea-   Imidazolidinone-   Sulfonylurea-   Oxamide-   Hexamethylphosphotriamide (HMPA)-   Oxazolidinone-   4-Isopropyloxazolidinone-   2-Methyl-2-oxazoline-   2-Ethyl-2-oxazoline-   Hydroxyurea-   Tetrahydro-2-pyrimidone-   Semicarbazide-   Biuret-   Glycoluril-   Hydantoin-   1-Methylhydantoin-   5,5-Dimethylhydantoin-   5-Hydantoin acetate-   Allantoin-   Parabanic acid-   Urazol-   4-Methylurazol-   5,6-Dihydrouracil-   Barbituric acid-   1,3-Dimethylbarbituric acid-   Dimethyloxamide-   Malondiamide-   Succinamide-   Adipamide-   Sebacic amide-   Fumaramide-   2-Oxazolidone-   3-Methyl-2-oxazolidinone-   2,5-Oxazolidinedione

It is preferable that the ink for ink jet recording of this inventioncontains a surfactant, thereby to adjust liquid properties of the ink,improving discharge stability of the ink and exerting an excellenteffect on improvement in water resistance of image and prevention of theprinted ink from blurring.

Examples of the surfactant include an anionic surfactant such as sodiumdodecyl sulfate, sodium dodecyloxysulfonate, and sodiumalkylbenzenesulfonate, a cationic surfactant such as cetylpyridiniumchloride, trimethylcetylammonium chloride, and tetrabutylammoniumchloride, and a nonionic surfactant such as polyoxyethylene nonylphenylether, polyoxyethylene naphthyl ether, and polyoxyethylene octylphenylether. Of these, the nonionic surfactants are particularly preferablyused.

The content of the surfactant in ink is from 0.001 to 15 mass percent,preferably from 0.005 to 10 mass percent, and more preferably from 0.01to 5 mass percent.

The ink for ink jet recording of this invention can be prepared bydissolving and/or dispersing the above-described azo dye orphthalocyanine dye and surfactant in an aqueous medium. In thisinvention, the “aqueous medium” means water or a mixture of water and asmall amount of a water-miscible organic solvent to which additives suchas wetting agent or stabilizer are added as needed.

Examples of the water-miscible organic solvent usable in this inventioninclude alcohols (e.g., methanol, ethanol, propanol, isopropanol,butanol, isobutanol, sec-butanol, t-butanol, pentanol, hexanol,cyclohexanol, and benzyl alcohol), polyhydric alcohols (e.g., ethyleneglycol, diethylene glycol, triethylene glycol, polyethylene glycol,propylene glycol, dipropylene glycol, polypropylene glycol, butyleneglycol, hexanediol, pentanediol, glycerin, hexanetriol, andthiodiglycol), glycol derivatives (e.g., ethylene glycol monomethylether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether,diethylene glycol monomethyl ether, diethylene glycol monobutyl ether,propylene glycol monomethyl ether, propylene glycol monobutyl ether,dipropylene glycol monomethyl ether, trietylene glycol monomethyl ether,ethylene glycol diacetate, ethylene glycol monomethyl ether acetate,triethylene glycol monomethyl ether, triethylene glycol monoethyl ether,and ethylene glycol monophenyl ether), amines (e.g., ethanolamine,diethanolamine, triethanolamine, N-methyldiethanolamine,N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine,diethylenetriamine, triethylenetetramine, polyethyleneimine, andtetramethylpropylenediamine), and other polar solvents (e.g., formamide,N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide,sulfolane, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone,2-oxazolidone, 1,3-dimethyl-2-imidazolidinone, acetonitrile, andacetone) Two or more of the above-described water-miscible organicsolvents can be jointly used.

In the preparation of the ink of this invention, in the case of awater-soluble ink, first, it is preferably dissolved in water. Then,various solvents and additives are added, dissolved, and mixed to make auniform ink liquid.

As methods of dissolution, various methods can be used, includingdissolution by agitation, dissolution by irradiation with an ultrasonicwave, and dissolution by shaking. Of these, the method of agitation isparticularly preferably used. When the agitation is carried out, in thisfield, various agitation systems such as agitation where shearing forceis utilized with the aid of known fluid agitation, a contrarotatingagitator, or a dissolver can be used. On the other hand, a method ofagitation where shearing force to the bottom surface of a vessel isutilized like a magnetic stirrer also is preferably utilized.

When the above-described azo dyes or phthalocyanine dyes are oil-solubledyes, the uniform ink liquid can be prepared by dissolving theoil-soluble dye in a high boiling organic solvent and then emulsifyingand dispersing the resulting solution in an aqueous medium.

The boiling points of high boiling organic solvents used in thisinvention are 150° C. or higher and preferably 170° C. or higher.

Examples of such high boiling organic solvents include phthalic esters(e.g., dibutyl phthalate, dioctyl phthalate, dicyclohexyl phthalate,di-2-ethylhexyl phthalate, decyl phthalate,bis(2,4-di-tert-amylphenyl)isophthalate, and bis(1,1-diethylpropyl)phthalate), esters of phosphoric acid or phosphonic acid (e.g., diphenylphosphate, triphenyl phosphate, tricresyl phosphate, 2-ethylhexyldiphenyl phosphate, dioctyl butyl phosphate, tricyclohexyl phosphate,tri-2-ethylhexyl phosphate, tridodecyl phosphate, and di-2-ethylhexylphenyl phosphate), benzoic esters (e.g., 2-ethylhexylbenzoate,2,4-dichlorobenzoate, dodecylbenzoate, and 2-ethylhexylp-hydroxybenzoate), amides (e.g., N,N-diethyldodecaneamide andN,N-diethyllaurylamide), alcohols or phenols (isostearyl alcohol,2,4-di-tert-amylphenol, etc.), aliphatic acid esters (e.g.,dibutoxyethyl succinate, di-2-ethylhexyl succinate, 2-hexyldecyltetradecanoate, tributyl citrate, diethyl azelate, isostearyl lactate,and trioctyl citrate), aniline derivatives(N,N-dibutyl-2-butoxy-5-tert-octylaniline, etc.), chlorinated paraffins(paraffins having chlorine contents of 10 to 80 percent), trimesicesters (e.g., tributyl trimesate), dodecylbenzene,diisopropylnaphthalene, phenols (e.g., 2,4-di-tert-amylphenol,4-dodecyloxyphenol, 4-dodecyloxycarbonylphenol, and4-(4-dodecyloxyphenylsulfonyl)phenol), carboxylic acids (e.g.,2-(2,4-di-tert-amylphenoxybutyric acid and 2-ethoxyoctanedecanoic acid),alkyl phosphates (e.g., di-(2-ethylhexyl)phosphate and diphenylphosphate), and the like. The mass ratio of the high-boiling organicsolvents used to the oil-soluble dyes is from 0.01 to 3 and preferablyfrom 0.01 to 1.0.

These high boiling organic solvents can be used singly or as mixtures ofsome solvents [e.g., tricresyl phosphate and dibutyl phthalate, trioctylphosphate and di(2-ethylhexyl) sebacate, and dibutyl phthalate andpoly(N-t-butylacrylamide)].

Other compounds than the compounds as described above as the highboiling organic solvents used in the invention and/or methods forsynthesizing these high boiling organic solvents are described, forexample, in U.S. Pat. Nos. 2,322,027, 2,533,514, 2,772,163, 2,835,579,3,594,171, 3,676,137, 3,689,271, 3,700,454, 3,748,141, 3,764,336,3,765,897, 3,912,515, 3,936,303, 4,004,928, 4,080,209, 4,127,413,4,193,802, 4,207,393, 4,220,711, 4,239,851, 4,278,757, 4,353,979,4,363,873, 4,430,421, 4,430,422, 4,464,464, 4,483,918, 4,540,657,4,684,606, 4,728,599, 4,745,049, 4,935,321, and 5,013,639, EuropeanPatent Nos. 276,319A, 286,253A, 289,820A, 309,158A, 309,159A, 309,160A,509,311A, and 510,576A, East Germany Patent Nos. 147,009, 157,147,159,573, and 225,240A, British Patent No. 2,091,124A, JP-A-48-47335,JP-A-50-26530, JP-A-51-25133, JP-A-51-26036, JP-A-51-27921,JP-A-51-27922, JP-A-51-149028, JP-A-52-46816, JP-A-53-1520,JP-A-53-1521, JP-A-53-15127, JP-A-53-146622, JP-A-54-91325,JP-A-54-106228, JP-A-54-118246, JP-A-55-59464, JP-A-56-64333,JP-A-56-81836, JP-A-59-204041, JP-A-61-84641, JP-A-62-118345,JP-A-62-247364, JP-A-63-167357, JP-A-63-214744, JP-A-63-301941,JP-A-64-9452, JP-A-64-9454, JP-A-64-68745, JP-A-1-101543, JP-A-1-102454,JP-A-2-792, JP-A-2-4239, JP-A-2-43541, JP-A-4-29237, JP-A-4-30165,JP-A-4-232946, JP-A-4-346338, and the like.

The mass ratio of the above-described high-boiling organic solvents usedto the oil-soluble dyes is from 0.01 to 3.0 and preferably from 0.01 to1.0.

In the invention, the oil-soluble dyes and high-boiling organic solventsare emulsified and dispersed in aqueous media and used. In theemulsification dispersion, low-boiling organic solvents can be used insome cases in view of emulsifiability. The low-boiling organic solventsare organic solvents having boiling points of about 30° C. or higher toabout 150° C. or lower at ordinary pressures. Examples of such solventsused preferably include esters (e.g., ethyl acetate, butyl acetate,ethyl propionate, β-ethoxyethyl acetate, and methyl cellosolve acetate),alcohols (e.g., isopropyl alcohol, n-butyl alcohol, and sec-butylalcohol), ketones (e.g., methyl isobutyl ketone, methyl ethyl ketone,and cyclohexanone), amides (e.g., dimethylformamide andN-methylpyrrolidone), ethers (e.g., tetrahydrofuran and dioxane), andthe like, but are not limited to these solvents.

The emulsification dispersion is carried out in order to make finedroplets of an oil phase by dispersing, in an aqueous phase containingmainly water, the oil phase having a dye dissolved in a high-boilingorganic solvent or in a mixed solvent thereof with a low-boiling organicsolvent in some cases. Additives such as surfactant, wetting agent, dyestabilizer, emulsion stabilizer, or antiseptic agent as described latercan be added as needed to either of the aqueous phase and the oil phaseor to both of them.

Although a method of adding the oil phase to the aqueous phase ingeneral is used as a method for emulsification, a method of addingdropwise the aqueous phase to the oil phase, the so-called phasereversal of emulsion, also can be preferably used. When the azo dyes orphthalocyanine dyes used in the invention are water-soluble and theadditives are oil-soluble, the above-described method of emulsificationcan be applied.

In the emulsification dispersion, various surfactants can be used.Examples of the surfactants used preferably include anionic surfactantssuch as fatty acid salt, alkyl sulfuric ester salt, alkylbenzenesulfonicsalt, alkylnaphthalenesulfonic salt, dialkyl sulfosuccinic salt, alkylphosphoric ester salt, formalin condensation product ofnaphthalenesulfonic acid, or polyoxyethylene alkyl sulfuric ester saltand nonionic surfactants such as polyoxyethylene alkyl ether,polyoxyethylene alkyl allyl ether, polyoxyethylene fatty acid ester,sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester,polyoxyethylene alkylamine, glycerin fatty acid ester, oxyethyleneoxypropylene block copolymer, and the like. Furthermore, SURFYNOLS (AirProducts & Chemicals Co.) which is an acetylene-series polyoxyethyleneoxide surfactant also is preferably used. In addition, amine oxide-typeamphoteric surfactants such as N,N-dimethyl-N-alkylamine oxide also arepreferred. Furthermore, substances described as surfactants inJP-A-59-157636 (pages 37 and 38) and Research Disclosure No. 308119(1989) also can be used.

For the purpose of promoting stabilization immediately afteremulsification, water-soluble polymers also can be jointly used with theabove-described surfactants. Polyvinyl alcohol, polyvinylpyrrolidone,polyethylene oxide, polyacrylic acid, polyacrylamide, or copolymers ofthese are preferably used as the water-soluble polymers. Furthermore,use of natural water-soluble polymers such as polysaccharide, casein, orgelatin also is preferred. In order to stabilize dispersions of dye,furthermore, polyvinyls obtained by polymerization of acrylic esters,methacrylic esters, vinyl esters, acrylamides, methacrylamides, olefins,styrenes, vinyl ethers, or acrylonitriles, or polyurethanes, polyesters,polyamides, polyureas, polycarbonates or the like that are notsubstantially dissolved in aqueous media also can be jointly used. It ispreferable that these polymers contain —SO₃ ⁻ or —COO⁻. In the joint useof these polymers that are substantially undissolved in the aqueousmedia, the polymers can be used preferably in amounts of 20 mass percentor less and more preferably in amounts of 10 mass percent or less of thehigh-boiling organic solvents.

In the case where an aqueous ink is prepared by dispersing anoil-soluble dye and a high-boiling organic solvent by emulsificationdispersion, control of the particle size thereof is particularlyimportant. In order to heighten color purity and density in theformation of image through ink jet, it is essential to reduce an averageparticle size. The size is preferably 1 μm or less and more preferablyfrom 5 to 100 nm in volume average particle diameter.

The volume average particle diameter and particle size distribution ofthe above-described dispersed particles can be readily measuredaccording to known methods as described in Jikken Kagaku Koza, 4thedition, pages 417 and 418, as well as a static light-scattering method,a dynamic light-scattering method, or a method of centrifugalsedimentation. For example, the particle concentration in ink is dilutedwith distilled water so as to become from 0.1 to 1 mass percent, and thevolume average particle diameter of the resulting diluted ink is easilymeasured with a commercially available volume average particlediameter-measuring instrument (e.g., MICROTRACK UPA (Produced by NikkisoK. K.)). Furthermore, the dynamic light-scattering method where thelaser Doppler effect is utilized is particularly preferred because themeasurement of particle sizes can be achieved until smaller sizes.

The volume average particle diameter is an average particle diameterweighed with particle volume and is a value where in an aggregate ofparticles the sum of the respective particle diameters multiplied by therespective particle volumes is divided by the total volume of particles.The volume average particle diameter is described in So-ichi Muroi,“Kobunshi Ratekkusu no Kagaku” (Published by Kobunshi Kankokai), page119.

It has become clear that the presence of coarse particles also has avery large effect on the printing capabilities. That is, it has beenfound out that the nozzle of a head is clogged with the coarse particlesor badly soiled, even if it is not clogged, to generate yore indischarging or non-discharging of ink, exerting a serious influence onthe printing capabilities. In order to prevent this fault, it isimportant, as to the ink prepared, to limit the number of particleshaving diameters of 5 μm or larger to 10 or less per μl of ink and thenumber of particles having diameters of 1 μm or larger to 1000 or lessper μl of ink.

In order to remove these coarse particles, known methods of centrifugalseparation, microfiltration, or the like can be used. These means ofseparation can be used immediately after emulsification dispersion orimmediately before charging ink into an ink cartridge after variousadditives such as wetting agent or surfactant are added to theemulsified dispersion.

As an effective means of reducing the average particle size and removingcoarse particles, mechanical emulsifying apparatus can be used.

Although known apparatus such as simple stirrer, impeller-agitatingsystem, in-line agitating system, a mill system including colloid mill,or ultrasonic wave system can be used as the emulsifying apparatus, useof a high-pressure homogenizer is particularly preferred.

The detailed mechanism of the high-pressure homogenizer is described inU.S. Pat. No. 4,533,254, JP-A-6-47264, and the like and the commerciallyavailable apparatus thereof includes Gaulin homogenizer (A.P.V. GaulinInc.), Microfluidizer (Microfluidex Inc.), Altimizer (Sugino MachineK.K.), and the like.

A high-pressure homogenizer equipped with a mechanism for dividingfinely particles in an ultra-high pressure jet stream as describedrecently in U.S. Pat. No. 5,720,551 is particularly effective for theemulsification dispersion of the invention. An example of theemulsifying apparatus where this ultra-high pressure jet stream is usedincludes De BEE 2000 (BEE INTERNATIONAL Ltd.).

The pressure on emulsifying in a high-pressure emulsification dispersionapparatus is 50 MPa or higher, preferably 60 MPa or higher, and furtherpreferably 180 MPa or higher.

For example, in a method of allowing an emulsion to pass through ahigh-pressure homogenizer after emulsifying in an agitating emulsifier,joint use of two or more kinds of emulsifiers is particularly preferred.Furthermore, a method of allowing an emulsion to pass through ahigh-pressure homogenizer again after adding additives such as wettingagent and surfactant after emulsifying and dispersing in theseemulsifiers and before charging ink into a cartridge also is a preferredmethod.

In the case where the low-boiling organic solvent is contained inaddition to the high-boiling organic solvent, it is preferable to removethe low-boiling solvent in view of the stability and the safety andsanitation of the resulting emulsion. In order to remove the low-boilingsolvent, various known methods can be used according to the kinds ofsolvents. That is, the methods include evaporation, vacuum evaporation,ultrafiltration, and the like. It is preferable to remove thelow-boiling organic solvent as fast as possible immediately afteremulsifying.

Methods for preparing inks for ink jet recording are described in detailin JP-A-5-148436, JP-A-5-295312, JP-A-7-97541, JP-A-7-82515, andJP-A-7-118584 and also can be utilized for the preparation of the inkfor ink jet recording of the invention.

For the ink for ink jet recording obtained in the invention, a drynesspreventive for preventing ink from clogging due to drying of dischargingink at the jet orifice, a penetration promoter that allows ink topenetrate much better into paper, a ultraviolet absorber, anantioxidant, a viscosity modifier, a surface tension modifier, adispersant, a dispersion stabilizer, a mildew proofing agent, ananti-corrosive agent, a pH adjuster, an antifoaming agent, a chelatingagent, and the like can be appropriately selected and used inappropriate quantities.

The dryness preventives used in the invention are preferablywater-soluble organic solvents having vapor pressures lower than water.Specific examples of such dryness preventives include polyhydricalcohols represented by ethylene glycol, propylene glycol, diethyleneglycol, polyethylene glycol, thiodiglycol, dithiodiglycol,2-methyl-1,3-propanediol, 1,2,6-hexanetriol, acetylene glycolderivatives, glycerin, and trimethylolpropane, lower alkyl ethers ofpolyhydric alcohols such as ethylene glycol monomethyl (or ethyl) ether,diethylene glycol monomethyl (or ethyl) ether, and triethylene glycolmonoethyl (or butyl) ether, heterocycles such as 2-pyrrolidone,N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, andN-ethylmorpholine, sulfur-containing compounds such as sulfolane,dimethyl sulfoxide, and 3-sulfolene, polyfunctional compounds such asdiacetone alcohol and diethanolamine, and urea derivatives. Of these,polyhydric alcohols such as glycerin and diethylene glycol are morepreferred. The above-described dryness preventives can be used singly oras mixtures of two or more thereof. It is preferable to contain thesedryness preventives in amounts of 10 to 50 mass percent of ink.

The penetration promoters used in the invention are alcohols such asethanol, isopropanol, butanol, di(tri)ethylene glycol monobutyl ether,and 1,2-hexanediol, sodium lauryl sulfate, sodium oleate, nonionicsurfactants, and the like. These penetration promoters, when 10 to 30mass percent thereof is contained in ink, exert a sufficient effect, andit is preferable to use the penetration promoters within the range ofamounts thereof that does not cause blurring in printing or kaminuke(print through).

The ultraviolet absorbers used to improve the keeping quality of imagein the invention include benzotriazole-series compounds as described inJP-A-58-185677, JP-A-61-190537, JP-A-2-782, JP-A-5-197075, andJP-A-9-34057, benzophenone-series compounds as described inJP-A-46-2784, JP-A-5-194483, and U.S. Pat. No. 3,214,463, cinnamicacid-series compounds as described in JP-B-48-30492, JP-B-56-21141, andJP-A-10-88106, triazine-series compounds as described in JP-A-4-298503,JP-A-8-53427, JP-A-8-239368, JP-A-10-182621, and JP-T-501291, andcompounds absorbing ultraviolet light and emitting fluorescence, theso-called fluorescent brightening agents, represented by compounds asdescribed in Research Disclosure No. 24239 and stilbene-series andbenzoxazole-series compounds.

Various organic or metal complex-series fading preventives can be usedas the antioxidants used to improve the keeping quality of image in theinvention. The organic fading preventives include hydroquinones,alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes,chromans, alkoxyanilines, heterocycles, and the like and the metalcomplex-series fading preventives include nickel complexes, zinccomplexes, and the like. More specifically, compounds as described inpatents cited in Research Disclosure No. 17643, VII, items I and J; No.15162; No. 18716, page 650, left column; No. 36544, page 527; No.307105, page 872; and No. 15162; and compounds which are shown bygeneral formula of representative compounds and included in examples ofcompounds as described in JP-A-62-215272, pages 127 to 137, can be used.

The mildewproofing agents used in the invention include sodiumdehydroacetate, sodium benzoate, sodium pyridinethion-1-oxide, ethylp-hydroxybenzoate, 1,2-benzisothiazoline-3-one and salts thereof, andthe like. These are preferably used in amounts of 0.02 to 5.00 masspercent in ink.

Details of these agents are described in “Bokin-Bobaizai Jiten” (Editedby Nippon Bokin-Bobaigakkai Jitenhenshu-iinkai) and the like.

Examples of the anti-corrosive agents include acidic sulfurous salts,sodium thiosulfate, ammonium thioglycolate, diisopropylammonium nitrite,pentaerythritol tetranitrate, dicyclohexylammonium nitrite,benzotriazole, and the like. These agents can be preferably used inamounts of 0.02 to 5.00 mass percent in ink.

The pH adjusters used in the invention can be suitably used in view ofadjustment of pH, the promotion of dispersion stability, and the like,and it is preferable to adjust the ink to pH 8 to 11 at 25° C. The pHless than 8 causes the nozzle to clog because of reduced solubility ofdye and exceeding pH 11 results in deteriorating the water resistance.The pH adjusters include organic bases and inorganic alkalis as basicadjusters and organic acids and inorganic acids as acidic adjusters.

The above-described organic bases include triethanolamine,diethanolamine, N-methyldiethanolamine, dimethylethanolamine, and thelike. The above-described inorganic alkalis include hydroxides of alkalimetals (e.g., sodium hydroxide, lithium hydroxide, potassium hydroxide,etc.), carbonic salts thereof (e.g., sodium carbonate, sodiumhydrogencarbonate, etc.), ammonium, and the like. The above-describedorganic acids include acetic acid, propionic acid, trifluoroacetic acid,alkylsulfonic acid, and the like. The above-described inorganic acidsinclude hydrochloric acid, sulfuric acid, phosphoric acid, and the like.

Apart from the above-described surfactants, in this invention, nonionic,cationic, or anionic surfactants are used as regulators of surfacetension. Examples of such surfactants include, as the anionicsurfactants, fatty acid salts, alkyl sulfuric ester salts,alkylbenzenesulfonic salts, alkylnaphthalenesulfonic salts, dialkylsulfosuccinic salts, alkyl phosphoric ester salts, formalin condensationproducts of naphthalenesulfonic acid, polyoxyethylene alkyl sulfuricester salts, and the like and, as the nonionic surfactants,polyoxyethylene alkyl ethers, polyoxyethylenealkylaryl ethers,polyoxyethylene fatty acid esters, sorbitan fatty acid esters,polyoxyethylene sorbitan fatty acid esters, polyoxyethylene alkylamines,glycerin fatty acid esters, oxyethylene oxypropylene block copolymers,and the like. SURFYNOLS (Air Products & Chemicals Co.) that areacetylene-series polyoxyethylene oxide surfactants also are preferablyused. Amphoteric surfactants of amine oxide type such asN,N-dimethyl-N-alkylamine oxide also are preferred. Furthermore,compounds described as surfactants in JP-A-59-157636, pages 37 and 38,and Research Disclosure No. 308119 (1989) also can be used.

The surface tension of the ink of the invention is preferably from 20 to60 mN/m and further preferably from 25 to 45 mN/m regardless of use ordisuse of these surfactants.

The viscosity of the ink used in the invention is preferably 30 mPa·s orless. Furthermore, since it is more preferable to regulate the viscosityto 20 mPa·s or less, viscosity modifiers are used in some cases for thepurpose of regulating the viscosity. Examples of the viscosity modifiersinclude cellulose, water-soluble polymers such as polyvinyl alcohol,nonionic surfactants, and the like. Further details are described in“Nendochosei Gijutsu” (Gijutsujoho Kyokai, 1999), Chapter 9 and“Chemicals for Ink Jet Printer” (a revised and enlarged edition,98)—Zairyo no Kaihatsu Doko Tenbo Chosa—” (CMC, 1997), pages 162 to 174.

In the invention, the respective surfactants of the aforesaid cationic,anionic, and nonionic types as the dispersants or dispersionstabilizers, fluorine-series and silicone-series compounds asantifoaming agents, and chlating agents represented by EDTA can also beused as needed.

The ink for ink jet recording of the invention also can be utilized forother uses than the use of ink jet recording. For example, the ink canbe utilized for materials for display image, image-forming materials forinterior decoration materials, image-forming materials for outdoordecoration materials, or the like.

The materials for display image indicate various articles such asposters, wall paper, small articles for decoration (ornaments, dolls,etc.), leaflets for commercial advertisement, packing paper, wrappingmaterials, paper bags, vinyl bags, packaging materials, signboards,images pictured on or attached to the side faces of public carriers(automobiles, buses, tram cars, etc.), and suits of clothes with logos.When the dyes of the invention are used as materials for forming displayimages, the images contain all patterns made of the dyes and recognizedby men, including abstract designs, letters, geometric patterns, and thelike, in addition to images of a narrow sense.

The materials for interior decoration indicate various articles such aswall paper, small articles for decoration (ornaments, dolls, etc.),members of light equipment, members of furniture, and design members offlooring and ceiling. When the dyes of the invention are used asmaterials for forming images, the images contain all patterns made ofthe dyes and recognized by men, including abstract designs, letters,geometrical patterns, and the like, in addition to images of s narrowsense.

The materials for outdoor decoration indicate various articles such aswall materials, roofing materials, signboards, gardening materials,small articles for outdoor decoration (ornaments, dolls, etc.), andmembers for outdoor light equipment. When the dyes of the invention areused as materials for forming images, the images contain all patternsmade of the dyes and recognized by men, including abstract designs,letters, geometrical patterns, and the like, in addition to images of anarrow sense.

In the above-described uses, the media on which patterns are formed caninclude paper, fiber, cloth (including non-woven fabric), plastics,metals, ceramics, and the like. Mordanting, textile printing, andfixation of dyestuffs with the aid of reactive dyes having reactivegroups introduced are possible as the forms of dyeing. Of these forms,dyeing by the mordanting form is preferred.

Recording charts and recording films used in the process for ink jetrecording of the invention are described. Supports of recording chartsand recording films used in the invention consist of chemical pulp suchas LBKP and NBKP, mechanical pulp such as GP, PGW, RMP, TMP, CTMP, CMP,and CGP, and recycled fiber such as DIP, are mixed as needed with knownadditives such as pigment, binder, sizing agent, bonding agent, cationicagent, or paper strength additive, and are manufactured on variousmachines such as fourdrinier paper machine or cylinder paper machine. Inaddition to these supports, any of synthetic paper and plastic filmsheets can be used as the supports, and it is desirable that thethickness of the supports is from 10 to 250 μm, and the basis weight isfrom 10 to 250 g/m².

An image-receiving material for the ink of the invention may be preparedby providing an image-receiving layer and a back coat layer directly ona support, or may be prepared by providing a size press or an anchorcoat layer by use of starch, polyvinyl alcohol, or the like and thenproviding the image-receiving layer and the back coat layer.Furthermore, the support can be subjected to a flattening treatment on acalendering machine such as machine calender, TG calender, and softcalender.

The support used more preferably in the invention is paper or plasticfilm having polyolefin (e.g., polyethylene, polystyrene, polybutene, andcopolymers thereof) or poly(ethylene terephthalate) laminated on bothsides thereof. It is preferable to add a white pigment (e.g., titaniumoxide or zinc oxide) or a tinting dye (e.g., cobalt blue, ultramarineblue, or neodymium oxide) to the polyolefin.

The image-receiving layer provided on the support is allowed to containtherein a porous material and an aqueous binder. Furthermore, theimage-receiving layer preferably contains a pigment, and the pigment ispreferably a white pigment. Examples of the white pigment includeinorganic white pigments such as calcium carbonate, kaolin, talc, clay,diatomaceous earth, synthetic amorphous silica, aluminum silicate,magnesium silicate, calcium silicate, aluminum hydroxide, alumina,lithopone, zeolite, barium sulfate, calcium sulfate, titanium dioxide,zinc sulfide, and zinc carbonate and organic pigments such asstyrene-series pigment, acrylic pigment, urea resin, and melamine resin.Porous white inorganic pigments are particularly preferred andparticularly, synthetic amorphous silica having a large pore area or thelike is suitable. Both of silicic acid anhydride obtained by a dryprocess (gas phase process) and moisture silicic acid obtained by a wetprocess can be used as the synthetic amorphous silica.

Recording charts containing the above-described pigments in theimage-receiving layers which can be used herein specifically includethose disclosed in JP-A-10-81064, JP-A-10-119423, JP-A-10-157277,JP-A-10-217601, JP-A-11-348409, JP-A-2001-138621, JP-A-2000-43401,JP-A-2000-211235, JP-A-2000-309157, JP-A-2001-96897, JP-A-2001-138627,JP-A-11-91242, JP-A-8-2087, JP-A-8-2090, JP-A-8-2091, JP-A-8-2093,JP-A-8-174992, JP-A-11-192777, JP-A-2001-301314, and the like.

Examples of the aqueous binder contained in the image-receiving layerinclude water-soluble polymers such as polyvinyl alcohol,silanol-modified polyvinyl alcohol, starch, cationic starch, casein,gelatin, carboxymethyl cellulose, hydroxyethyl cellulose,polyvinylpyyrolidone, polyalkylene oxide, and polyalkylene oxidederivatives and water-dispersible polymers such as styrene butadienelatex and acrylic emulsion. These aqueous binders can be used singly oras mixtures of two or more thereof. Of these, the polyvinyl alcohol andthe silanol-modified polyvinyl alcohol are particularly suitable in theinvention in view of the adhesion to pigment and the release resistanceof an ink-accepting layer.

The image-receiving layer can contain a mordant, a water resistancepromoter, a light resistance improver, a gas resistance improver, asurfactant, a hardener, and other additives in addition to the pigmentand the aqueous binder.

It is preferable that the mordant added to the image-receiving layer isunmovable. A polymer mordant is preferably used therefor.

The polymer mordant is described in the respective descriptions ofJP-A-48-28325, JP-A-54-74430, JP-A-54-124726, JP-A-55-22766,JP-A-55-142339, JP-A-60-23850, JP-A-60-23851, JP-A-60-23852,JP-A-60-23853, JP-A-60-57836, JP-A-60-60643, JP-A-60-118834,JP-A-60-122940, JP-A-60-122941, JP-A-60-122942, JP-A-60-235134, andJP-A-1-161236 and U.S. Pat. Nos. 2,484,430, 2,548,564, 3,148,061,3,309,690, 4,115,124, 4,124,386, 4,193,800, 4,273,853, 4,282,305, and4,450,224. Image-receiving materials containing polymer mordants asdescribed in JP-A-1-161236, pages 212 to 215, are particularlypreferred. Use of the polymer mordants as described in this patentenables formation of an image of excellent quality and improvement inlight resistance of the image.

The water resistance promoter is effective for the water resistance ofimage, and cationic resins are particularly desirable as the waterresistance promoters. Such cationic resins include polyamide polyamineepichlorhydrin, polyethylene imine, polyamine sulfone,dimethyldiallyl-ammonium chloride polymer, cationic polyacrylic amide,and the like. The content of these cationic resins in the total solidcomponents of the ink-accepting layer is preferably from one to 15 masspercent and particularly preferably from three to 10 mass percent.

The light resistance improvers and the gas resistance improvers includephenol compounds, hinderded phenol compounds, thioether compounds,thiourea compounds, thiocyanic acid compounds, amine compounds,hinderded amine compounds, TEMPO compounds, hydrazine compounds,hydrazide compounds, amidine compounds, vinyl group-containingcompounds, ester compounds, amide compounds, ether compounds, alcoholcompounds, sulfinic acid compounds, succharides, water-soluble reductivecompounds, organic acids, inorganic acids, hydroxy group-containingorganic acids, benzotriazole compounds, benzophenone compounds, triazinecompounds, heterocyclic compounds, water-soluble metallic salts,organometallic compounds, metal complexes, and the like.

Specific examples of these compounds include those described inJP-A-10-182621, JP-A-2001-260519, JP-A-2000-260519, JP-B-4-34953,JP-B-4-34513, JP-B-4-34512, JP-A-11-170686, JP-A-60-67190,JP-A-7-276808, JP-A-2000-94829, JP-T-8-512258, JP-A-11-321090, and thelike.

The surfactants function as a coating aid, a release improver, a slipimprover, or an antistatic agent. The surfactants are described in therespective descriptions of JP-A-62-173463 and JP-A-62-183457.

Organic fluorine compounds can be used in place of the surfactants. Theorganic fluorine compounds are preferably hydrophobic. Examples of theorganic fluorine compounds include fluorine-series surfactants, oilyfluorine-series compounds (e.g., fluorine oil), and solid fluorinecompound resins (e.g., tetrafluoroethylene resin). The organic fluorinecompounds are described in JP-B-57-9053 (8th to 17th columns),JP-A-61-20994, and JP-A-62-135826.

Materials used as the hardeners are those described in JP-A-1-161236,Page 222, JP-A-9-263036, JP-A-10-119423, and JP-A-2001-310547.

Furthermore, additives added to other image-receiving layers include apigment dispersant, a thickener, an antifoaming agent, a dye, afluorescent brightening agent, an antiseptic agent, a pH adjuster, amatting agent, a hardener, and the like. The ink-accepting layer may beof one layer or two layers.

A back coat layer can be provided on the recording chart and therecording film, and components that can be added to this layer are awhite pigment, an aqueous binder, and other components.

Examples of the white pigment contained in the back coat layer includewhite inorganic pigments such as precipitated calcium carbonate light,calcium carbonate heavy, kaolin, talc, calcium sulfate, barium sulfate,titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, satin white,aluminum silicate, diatomaceous earth, calcium silicate, magnesiumsilicate, synthetic amorphous silica, colloidal silica, colloidalalumina, pseudoboehmite, aluminum hydroxide, alumina, lithopone,zeolite, hydrohalloysite, magnesium carbonate, and magnesium hydroxideand organic pigments such as styrene-series plastic pigment, acrylicplastic pigment, polyethylene, microcapsule, urea resin, and melamineresin.

The aqueous binders contained in the back coat layer includewater-soluble polymers such as styrene/maleic salt copolymer,styrene/acrylic salt copolymer, polyvinyl alcohol, silanol-modifiedpolyvinyl alcohol, starch, cationic starch, casein, gelatin,carboxymethyl cellulose, hydroxyethyl cellulose, andpolyvinylpyrrolidones and water-dispersible polymers such as styrenebutadiene latex, and acrylic emulsion, ant the like. Other componentscontained in the back coat layer include an antifoaming agent, a foamsuppressor, a dye, a fluorescent brightening agent, an antiseptic agent,a water resistance promoter, and the like.

A dispersion of finely divided particles of polymer can be added tolayers constituting the ink jet recording chart and recording film(including back layers). The dispersion of finely divided particles ofpolymer is used for the purpose of improving film properties such asdimensional stability, prevention of curling, prevention of blocking,and prevention of crazing of film. The dispersion of finely dividedparticles of polymer is described in the respective descriptions ofJP-A-62-245258, JP-A-62-1316648, and JP-A-62-110066. The dispersion offinely divided particles of polymer having a low glass transitiontemperature (40° C. or lower), which is added to the layer containing amordant, can prevent the layer from crazing and curling. Furthermore,the curling can be prevented by adding the dispersion of finely dividedparticles of polymer having a high glass transition temperature to theback layer also.

Systems of ink jet recording applicable to the ink of the invention arenot limited, and the ink of the invention can be used for known systems,for example, a charge control system where the ink is discharged withthe aid of electrostatic attraction force, a drop-on demand system(pressure pulse system) where the vibratory pressure of a piezoresistoris utilized, an acoustic ink jet system where ink is discharged bychanging electric signals to acoustic beams, irradiating the ink withthe acoustic beams, and utilizing the resulting radiation pressure, athermal ink jet (bubble jet) system where ink is heated to form bubblesand the resulting pressure is utilized, and the like.

The ink jet recording system includes a system of ejecting a number ofsmall volumes of an ink having a low concentration called photo-ink, asystem of improving an image by use of a plurality of inks havingsubstantially the same color hue but different concentrations, and asystem of using a colorless transparent ink.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention is hereinafter illustrated through examples, butis not to be construed as limited to these.

EXAMPLE 1

After deionized water was added to the following ingredients so as tobecome 1 liter, the resulting mixture was stirred for 1 hr while heatingat 30 to 40° C. The mixture was then filtered under reduced pressurethrough a microfilter having an average pore diameter of 0.25 μm toprepare a light magenta ink. [Formulation of Light Magenta Ink LM-101](Solid Ingredients) Magenta dye (a-36) 7.5 g/l PROXEL 5 g/l (LiquidIngredients) Diethylene glycol 90 g/l Glycerin 70 g/l Triethylene glycolmonobutyl ether 70 g/l Triethanolamine 6.9 g/l Surfynol STG 10 g/l

Furthermore, a magenta ink liquid, M-101, where magenta dyestuff (a-36)was increased to 23 g in the above-described formulation was prepared.[Formulation of Magenta Ink M-101] (Solid Ingredients) Magenta dye(a-36) 23 g/l PROXEL 5 g/l (Liquid Ingredients) Diethylene glycol 90 g/lGlycerin 70 g/l Triethylene glycol monobutyl ether 70 g/lTriethanolamine 6.9 g/l Surfynol STG 10 g/l

The oxidation potential of magenta dye (a-36) used herein is morepositive than 1.0 V (vs SCE).

Inks LM-102 to LM-108 and M-102 to M-108 having the quite sameformulations were prepared, respectively, except that additives as shownbelow were added to LM-101 to M-101. Additives LM-101, M-101(Comparative Example) None LM-102, M-102 (Comparative Example) 50 g/l ofdiethylene glycol to LM-101 and M-101 LM-103, M-103 (ComparativeExample) 50 g/l of glycerin to LM-101 and M-101 LM-104, M-104(Comparative Example) 50 g/l of triethylene glycol monobutyl ether toLM-101 and M-101 LM-105, M-105 (This Invention) 10 g/l of 2-pyrrolidoneto LM-101 and M-101 LM-106, M-106 (This Invention) 10 g/l of sulfolaneto LM-101 and M-101 LM-107, M-107 (This Invention) 10 g/l of1,3-dimethylimidazolidinone to LM-101 and M-101 LM-108, M-108 (ThisInvention) 10 g/l of ε-caprolactam to LM-101 and M-101

These inks were charged into cartridges for magenta ink and lightmagenta ink of Ink Jet Printer PM-950C produced by EPSON Co. and theinks of PM-950C were used as other color inks to print single colorimages of magenta different in density. The images were printed on InkJet Paper Photo Glossy Paper EX manufactured by Fuji Photo Film Co.,Ltd. as image-accepting sheets and evaluations of the dischargestability of the inks and the fastness of the images were carried out.

(Experiments for Evaluation)

1) The discharge stability was evaluated as follows: after thecartridges were set in the printer and discharge of the inks from allnozzles was confirmed, 20 sheets of A4 were printed out and evaluated onthe basis of the following standards.

-   -   A: No turbulence in printing occurs from the beginning to the        end of printing.    -   B: Output causing turbulence in printing occurs.    -   C: Turbulence in printing occurs from the beginning to the end        of printing.

This experiment was carried out just after charging the inks (dischargestability A) and after storing the ink cartridges under the conditionsof 40° C.-80% RH for two weeks (discharge stability B).

2) The keeping quality of image was evaluated as to samples of printedmagenta solid image prepared in the following manner.

(1) About the light resistance, image density C_(i) was measured with areflection densitometer (X-Rite 310TR) immediately after printing, theimage was then irradiated with Xenon light (85,000 lux) for 10 days byuse of a weather meter produced by Atlas Co., then the image densityC_(f) was measured again to find the residual ratio of dye(100×C_(f)/C_(i)) for evaluation. The residual ratios of dye wereevaluated at three points of 1, 1.5, and 2 in reflection density, andwhen the residual ratios of dye were 70 percent or more at alldensities, the sample was graded A; when the residual ratios of dye wereless than 70 percent at two points, the sample was graded B; and whenthe residual ratios of dye were less than 70 percent at all densities,the sample was graded C.

(2) About the heat resistance, the densities of a sample were measuredwith the reflection densitometer (X-Rite 310TR) before and after thesample was stored under the conditions of 80° C.-15% RH for 10 days tofind the residual ratio of dye for evaluation. The residual ratio of dyewas evaluated at three points of 1, 1.5, and 2 in reflection density,and when the residual ratios of dye were 90 percent or more at alldensities, the sample was graded A; when the residual ratios of dye wereless than 90 percent at two points, the sample was graded B; and whenthe residual ratios of dye were less than 90 percent at all densities,the sample was graded C.

(3) About the ozone resistance, the above-described sheets of the photoglossy paper having image were allowed to stand for 7 days in a box setto an ozone gas concentration of 0.5 ppm and the image densities weremeasured by use of a reflection densitometer (X-Rite 310TR) before andafter the sheets were allowed to stand, to evaluate the ozone resistanceas the residual ratio of dyestuff. The reflection densities weremeasured at three points of 1, 1.5, and 2.0. The concentration of ozonegas in the box was set by use of an ozone gas monitor (Model OZG-EM-01)produced by APPLICS Co.

The results were evaluated in the following three steps: when theresidual ratios of dyestuff were 80 percent or more at all densities,the sample was graded A; when the residual ratios of dyestuff were lessthan 80 percent at one or two points, the sample was graded B; and whenthe residual ratios were less than 70 percent at all densities, thesample was graded C.

Results thus obtained are shown in the following table. DischargeDischarge Light Heat Ozone Stability A Stability B Resistance ResistanceResistance Magenta ink, light magenta ink of A A C B C PM-950C, EPSONCo. (Comparative Example) LM-101, M-101 A C A A A (Comparative Example)LM-102, M-102 A C A A A (Comparative Example) LM-103, M-103 A C A A A(Comparative Example) LM-104, M-104 A C A A A (Comparative Example)LM-105, M-105 (This Invention) A A A A A LM-106, M-106 (This Invention)A A A A A LM-107, M-107 (This Invention) A A A A A LM-108, M-108 (ThisInvention) A A A A A

The results of the above table reveal that this invention satisfies allcapabilities and is superior to the comparative examples.

Furthermore, the inks of the invention obtained a color hue equal tothat of the inks of PM-950C of EPSON Co.

The inks of the invention prepared by using other dyes represented bygeneral formula (1) in place of magenta dye (a-36) in Example 1 alsoobtained the same capabilities and effect of color hue as in Example 1.

EXAMPLE 2

A light magenta ink was prepared similarly to Example 1 except that thefollowing ingredients were used. [Formulation of Light Magenta InkLM-101] (Solid Ingredients) Magenta Dye (a-36) 7.5 g/l PROXEL 3.5 g/l(Liquid Ingredients) Diethylene Glycol 150 g/l Glycerin 130 g/lTriethylene Glycol Monobutyl Ether 130 g/l Triethanolamine 6.9 g/lSurfynol STG 10 g/l

Furthermore, magenta ink liquid M-101 where magenta dye (a-36) wasincreased to 23 g in the above-described formulation was prepared.[Formulation of Magenta Ink M-101] (Solid Ingredients) Magenta Dye(a-36) 23 g/l PROXEL 3.5 g/l (Liquid Ingredients) Diethylene Glycol 150g/l Glycerin 130 g/l Triethylene Glycol Monobutyl Ether 130 g/lTriethanolamine 6.9 g/l Surfynol STG 10 g/l

Inks LM-102 to 108 and M-102 to 108 having the same compositions as inLM-101 and M-101 were prepared except that additives were added as shownbelow. Additives LM-101, M-101 (Comparative Example) None LM-102, M-102(Comparative Example) 20 g/l of ethylene glycol to LM-101 and M-101LM-103, M-103 (Comparative Example) 40 g/l of ethylene glycol to LM-101and M-101 LM-104, M-104 (This Invention) 20 g/l of N,N-dimethylurea toLM-101 and M-101 LM-105, M-105 (This Invention) 40 g/l ofN,N-dimethylurea to LM-101 and M-101 LM-106, M-106 (This Invention) 40g/l of ethyleneurea to LM-101 and M-101 LM-107, M-107 (This Invention)40 g/l of sulfonylurea to LM-101 and M-101 LM-108, M-108 (ThisInvention) 20 g/l of HMPA to LM-101 and M-101

The discharge stability and image fastness of these inks were evaluatedsimilarly to Example 1.

Results thus obtained are shown in the following table. DischargeDischarge Light Heat Ozone Stability A Stability B Resistance ResistanceResistance Pure Ink (PM-950C), EPSON Co. A A C B C LM-101, M-101 A C A AA (Comparative Example) LM-102, M-102 A C A A A (Comparative Example)LM-103, M-103 A C A A A (Comparative Example) LM-104, M-104 (ThisInvention) A A A A A LM-105, M-105 (This Invention) A A A A A LM-106,M-106 (This Invention) A A A A A LM-107, M-107 (This Invention) A A A AA LM-108, M-108 (This Invention) A A A A A

The results of the above-described table reveal that the systems wherethe ink sets of this invention are used are superior to those of thecomparative examples in view of the discharge stability. Furthermore,the results also shows that the inks of this invention are superior tothe inks of EPSON Co. (PM-950C pure ink) in view of the resistance tolight, heat, and oxidative gas of dyestuff.

EXAMPLE 3

A light cyan ink was prepared similarly to Example 1 except that thefollowing ingredients were used. [Formulation of Light Cyan Ink LC-101](Solid Ingredients) Cyan Dye of This Invention (154) 17.5 g/l PROXEL 5g/l (Liquid Ingredients) Diethylene Glycol (DEG) 90 g/l Glycerin (GR) 70g/l Triethylene Glycol Monobutyl Ether (TGB) 70 g/l Triethanolamine 6.9g/l Surfynol STG 10 g/l Triethanolamine (TEA) 6.9 g/l Surfynol STG (SW)10 g/l

Furthermore, cyan ink liquid C-101 where cyan dye (154) was increased to68 g in the above formulation was prepared. [Formulation of Cyan InkC-101] (Solid Ingredients) Cyan Dye of this invention (154) 68 g/lPROXEL 5 g/l (Liquid Ingredients) Diethylene Glycol (DEG) 90 g/lGlycerin (GR) 70 g/l Triethylene Glycol Monobutyl Ether (TGB) 70 g/lTriethanolamine 6.9 g/l Surfynol STG 10 g/l Triethanolamine (TEA) 6.9g/l Surfynol STG (SW) 10 g/l

The oxidation potential of cyan dye (154) used herein is more positivethan 1.0 V (vs SCE).

Inks LC-102-108 and C-102-108 having the same composition were prepared,respectively, except that additives were added to LC-101 and C-101 asshown in the following table. Additive LC-101, C-101 (ComparativeExample) None LC-102, C-102 (Comparative Example) 50 g/l of diethyleneglycol to LC-101 and C-101 LC-103, C-103 (Comparative Example) 50 g/l ofglycerin to LC-101 and C-101 LC-104, C-104 (Comparative Example) 50 g/lof triethylene glycol monobutyl ether to LC-101 and C-101 LC-105, C-105(This Invention) 10 g/l 2-pyrrolidone to LC-101 and C-101 LC-106, C-106(This Invention) 10 g/l of Sulfolane to LC-101 and C-101 LC-107, C-107(This Invention) 10 g/l of 1,3-dimethylimidazolidinone to LC-101 andC-101 LC-108, C-108 (This Invention) 10 g/l of ε-caprolactam to LC-101and C-101

The cartridges for cyan ink and light cyan ink of Ink Jet PrinterMP-950C produced by EPSON Co. were charged with these inks and the inksof PM-950C were used for inks of other colors to print singe colorimages of cyan. The images were printed on Ink Jet Paper Photo GlossyPaper EX manufactured by Fuji Photo Film Co., Ltd. as image-acceptingsheets and evaluations of the discharge stability of the inks and thefastness of the images were carried out.

(Experiments for Evaluation)

1) About the discharge stability, the cartridges were set in theprinter, the discharge of inks from all nozzles was confirmed, and then20 sheets of A4 were printed out and evaluated on the basis of thefollowing standards.

-   -   A. No turbulence in printing occurs from the beginning to the        end of printing.    -   B. Output causing turbulence in printing occurs.    -   C. Turbulence in printing occurs from the beginning to the end        of printing.

This experiment was carried out about inks immediately after chargingwith inks (discharge stability A) and about inks that were repeatedlystored in a constant temperature box of 60° C. for 12 hr and in aconstant temperature box of −60° C. for 12 hr and were restored to roomtemperature after the elapse of two weeks (discharge stability B).

2) About the keeping quality of image, printed samples of cyan solidimage were prepared and (1) light resistance, (2) heat resistance, and(3) ozone resistance were evaluated similarly to Example 1.

Results thus obtained are shown in the following table. DischargeDischarge Light Heat Ozone Stability A Stability B Resistance ResistanceResistance Pure Ink, EPSON Co. A A C B C LC-101, C-101 (ComparativeExample) A C A A A LC-102, C-102 (Comparative Example) A C A A A LC-103,C-103 (Comparative Example) A C A A A LC-104, C-104 (ComparativeExample) A C A A A LC-105, C-105 (This Example) A A A A A LC-106, C-106(This Example) A A A A A LC-107, C-107 (This Example) A A A A A LC-108,C-108 (This Example) A A A A A

The results of the above table reveal that the inks of the inventionsatisfy all capabilities and are superior to those of the comparativeexamples.

Furthermore, the inks having the same color hue as in the ink of PM-950Cmanufactured by EPSON Co. were obtained in this invention.

EXAMPLE 4

A light cyan ink was prepared similarly to Example 1 except that thefollowing ingredients were used. [Formulation of Light Cyan Ink LC-101](Solid Ingredients) Cyan Dye of This Invention (154) 17.5 g/l PROXEL 3.5g/l (Liquid Ingredients) Diethylene Glycol 150 g/l Glycerin 130 g/lTriethylene Glycol Monobutyl Ether 130 g/l Triethanolamine 6.9 g/lSurfynol STG 10 g/l

PREPARATION OF CYAN INK C-101 (COMPARATIVE EXAMPLES)

Furthermore, cyan ink liquid C-101 where cyan dye (154) was increased to68 g in the above formulation were prepared. [Formulation of Cyan InkC-101] (Solid Ingredients) Cyan Dye of the Invention 68 g/l (ExemplifiedCompound 154) PROXEL 3.5 g/l (Liquid Ingredients) Diethylene Glycol 150g/l Glycerin 130 g/l Triethylene Glycol Monobutyl Ether 130 g/lTriethanolamine 6.9 g/l Surfynol STG 10 g/l

PREPARATION OF CYAN INKS OF THIS INVENTION AND OTHER COMPARATIVEEXAMPLES

Inks LC-102 to 108 and C-102 to 108 having the same composition asdescribed above were prepared, respectively, except that additives asshown in the following table were added to the above-described cyan inksLC-101 and C-101. Additive LC-101, C-101 (Comparative Example) NoneLC-102, C-102 (Comparative Example) 20 g/l of ethylene glycol to LC-101and C-101 LC-103, C-103 (Comparative Example) 40 g/l of ethylene glycolto LC-101 and C-101 LC-104, C-104 (This Invention) 20 g/l ofN,N-dimethylurea to LC-101 and C-101 LC-105, C-105 (This Invention) 40g/l of N,N-dimethylurea to LC-101 and C-101 LC-106, C-106 (ThisInvention) 40 g/l of ethyleneurea to LC-101 and C-101 LC-107, C-107(This Invention) 40 g/l of Sulfonylurea to LC-101 and C-101 LC-108,C-108 (This Invention) 20 g/l of HMPA to LC-101 and C-101

About these inks, single color images of cyan were printed similarly toExample 3 and the discharge stability of ink and the fastness of imagewere evaluated similarly to Example 1.

Results thus obtained are shown in the following table. DischargeDischarge Light Heat Ozone Stability A Stability B Resistance ResistanceResistance Pure Ink (PM-950C), EPSON Co. A A B B C LC-101, C-101(Comparative Example) A C A A A LC-102, C-102 (Comparative Example) A CA A A LC-103, C-103 (Comparative Example) A C A A A LC-104, C-104 (ThisInvention) A A A A A LC-105, C-105 (This Invention) A A A A A LC-106,C-106 (This Invention) A A A A A LC-107, C-107 (This Invention) A A A AA LC-108, C-108 (This Invention) A A A A A

The results of the table reveal that the systems where the ink sets ofthis invention are used are superior to those of comparative examples inview of the discharge stability and furthermore, the systems aresuperior to the ink of EPSON Co. (pure ink PM-950C) in view of the lightresistance, heat resistance, and oxidative gas resistance of dyestuff.

INDUSTRIAL APPLICABILITY

According to the present invention, in aqueous inks advantageous in viewof handling properties, odor, and safety, inks for ink jet recording canbe provided which are good in color hue and excellent in dischargestability, weathering resistance, water resistance, light resistance,heat stability, and oxidation resistance even after aging for a longperiod of time.

1. An ink for ink jet recording comprising a dye dissolved or dispersesin an aqueous medium, wherein the dye is a water-soluble dye having anoxidation potential more positive than 1.0 V (vs SCE) and the inkcomprises at least one selected from compounds represented by thefollowing general formula (A) and compounds represented by the followinggeneral formula (B):

in the formula, X represents a group containing carbonyl or aheteroatom; Z₁ represents a group of atoms that can form a cyclicorganic substance: General formula (B)X¹—Y-Z in the formula, X¹ represents a group shown by —N(Q₁)-Q₂; Zrepresents a group shown by —N(Q₁)-Q₂ or a group shown by —O-Q₃; Yrepresents a group shown by —W-(G)_(k)-(H)_(n)—; W and H representgroups shown by —CO—, —SO₂—, or —PO(Q₄)-; G represents a divalentconnecting group; Q₁ to Q₄ represent any of a hydrogen atom, an aminogroup, an alkyl group, an alkenyl group, an alkynyl group, an arylgroup, a heterocyclic group, a heteroaryl group, an alkoxy group, anaryloxy group, a heterocyclic oxy group, a heteroaryloxy group, analkylamino group, an arylamino group, a heterocyclic amino group, and aheteroarylamino group; X and Z may combine with each other to form aring; K and n each represent 0 or
 1. 2. The ink for ink jet recording asdescribed in claim 1, wherein the dye is a magenta dye selected from anazo dye, and the magenta dye has an absorption maximum in a spectralregion of 500 to 580 nm in the aqueous medium.
 3. The ink for ink jetrecording as described in claim 2, wherein the azo dye has a chromophorerepresented by general formula: (heterocycle A)-N═N-(heterocycle B), inwhich the heterocycle A and the heterocycle B in the above generalformula may have the same structure.
 4. The ink for ink jet recording asdescribed in claim 2 or 3, wherein the azo dye is an azo dye having anaromatic nitrogen-containing six-membered heterocycle linked directly toat least one side of the azo group as a coupling component.
 5. The inkfor ink jet recording as described in claim 3 or 4, wherein the azo dyeis an azo dye having an aromatic amino group- or a heterocyclic aminogroup-containing structure as an auxochrome.
 6. The ink for ink jetrecording as described in any of claims 2 to 5, wherein the azo dye isan azo dye having a steric structure.
 7. The ink for ink jet recordingas described in any of claims 2 to 6, wherein the azo dye is a dyerepresented by the following general formula (1):

In general formula (1), A represents a five-membered heterocyclic group;B¹ and B² each represents ═CR¹— or —CR²═, or either thereof represents anitrogen atom and the other represents ═CR¹— or —CR²═; R⁵ and R⁶ eachindependently represent a hydrogen atom or a substituent group, thesubstituent group represents an aliphatic group, an aromatic group, aheterocyclic group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, a carbamoyl group, an alkylsulfonyl group, anarylsulfonyl group, or a sulfamoyl group, and a hydrogen atom(s) on therespective substituent groups may be substituted; G, R¹, and R² eachindependently represent a hydrogen atom or a substituent group, thesubstituent group represents a halogen atom, an aliphatic group, anaromatic group, a heterocyclic group, a cyano group, a carboxyl group, acarbamoyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, aheterocyclic oxycarbonyl group, an acyl group, a hydroxy group, analkoxy group, an aryloxy group, a heterocyclic oxy group, a silyloxygroup, an acyloxy group, a carbamoyloxy group, an alkoxycarbonyloxygroup, an aryloxycarbonyloxy group, an amino group, an acylamino group,an ureido group, a sulfamoylamino group, an alkoxycarbonylamino group,an aryloxycarbonylamino group, an alkylsulfonylamino group, anarylsulfonylamino group, a heterocyclic sulfonylamino group, a nitrogroup, an alkylthio group, an arylthio group, a heterocyclic thio group,an alkylsulfonyl group, an arylsulfonyl group, a heterocyclic sulfonylgroup, an alkylsulfinyl group, an arylsulfinyl group, a heterocyclicsulfinyl group, a sulfamoyl group, or a sulfo group, and a hydrogenatom(s) on the respective substituent groups may be substituted; R¹ andR⁵, or R⁵ and R⁶ may be combined to form a five- or six-membered ring.8. The ink for ink jet recording as described in any of claims 2 to 7,wherein a rate constant of ozone fading of a recorded image is 5.0×10⁻²[hour⁻¹] or less.
 9. The ink for ink jet recording as described in claim1, wherein the dye is a phthalocyanine dye.
 10. The ink for ink jetrecording as described in claim 9, wherein a residual ratio of dye(density after fading/initial density×100) is 60 percent or more whenkept in an ozone atmosphere of 5 ppm for 24 hr, in a monochromatic siteprinted so that the cyan reflection density in a status A filter is from0.9 to 1.1 by use of a monochrome of the ink (cyan).
 11. The ink for inkjet recording as described in claims 9 or 10, wherein an amount of Cuion running off into water is 20 percent or less of the total dye afterthe ink undergoes ozone fading under the condition of claim
 10. 12. Theink for ink jet recording as described in any of claims 9 to 11, whereinthe phthalocyanine dye is a water-soluble dye having anelectron-withdrawing group at a β position of a benzene ring of thephthalocyanine.
 13. The ink for ink jet recording as described in any ofclaims 9 to 12, wherein the phthalocyanine dye is a water-solublephthalocyanine dye prepared by a process that does not go through asulfonation of non-substituted phthalocyanine.
 14. The ink for ink jetrecording as described in any of claims 9 to 13, wherein thephthalocyanine dye is represented by the following general formula (I):

in the above formula (I), X₁, X₂, X₃, and X₄ each independentlyrepresent —SO-Z, —SO₂-Z, —SO₂NR1R2, a sulfo group, —CONR1R2, or —CO₂R1;the above Z represents a substituted or unsubstituted alkyl group, asubstituted or unsubstituted cycloalkyl group, a substituted orunsubstituted alkenyl group, a substituted or unsubstituted aralkylgroup, a substituted or unsubstituted aryl group, or a substituted orunsubstituted heterocyclic group; the above R1 and R2 each independentlyrepresent a hydrogen atom, a substituted or unsubstituted alkyl group, asubstituted or unsubstituted cycloalkyl group, a substituted orunsubstituted alkenyl group, a substituted or unsubstituted aralkylgroup, a substituted or unsubstituted aryl group, or a substituted orunsubstituted heterocyclic group, and when a plurality of Z's exist, theZ's may be the same or different; Y₁, Y₂, Y₃, and Y₄ each independentlyrepresent a monovalent substituent group; when any of X₁ to X₄ and Y₁ toY₄ exists in plurality, they may be the same or different; a₁ to a₄ andb₁ to b₄ represent the number of substituent groups X₁ to X₄ and Y₁ toY₄, respectively, and a₁ to a₄ each independently represent an integerof 0 to 4, all of them do not represent 0 at the same time, and b₁ to b₄each independently represent an integer of zero to four; M is a hydrogenatom, a metallic atom, or an oxide, a hydroxide or a halide thereof. 15.The ink for ink jet recording as described in claim 14, wherein the dyerepresented by general formula (I) is a dye represented by the followinggeneral formula (II):

in the above general formula (II), X₁₁ to X₁₄, Y₁₁ to Y₁₄, and M havethe same meanings as X₁ to X₄, Y₁ to Y₄, and M in general formula (I),respectively; a₁₁ to a₁₄ each independently represent an integer of 1 or2.
 16. The ink for ink jet recording as described in any of claims 1 to15, which comprises an organic solvent having a boiling point of 150° C.or higher.
 17. A method of ink jet recording, which comprises using theink for ink jet recording as described in claims 1 to
 16. 18. A methodof ink jet recording, which comprises discharging ink droplets accordingto a recording signal onto an image-receiving material that has animage-receiving layer containing particles of a white inorganic pigmenton a support to record an image on the image-receiving material, whereinthe ink droplets comprises the ink for ink jet recording as described inclaims 1 to 16.